Use of polymer powder containing UV absorber for the stabilisation of polymers against the effects of UV radiation

ABSTRACT

The present invention relates to the use, for stabilizing polymers, in particular polyolefins, with respect to exposure to UV radiation, of fine-particle polymer powders comprising at least one UV absorber. The present invention further relates to stabilizer mixtures for stabilizing polymers with respect to exposure to UV radiation, oxygen and heat, which, inter alia, comprise these polymer powders, and to a process for stabilizing polymers, in particular polyolefins, with respect to exposure to UV radiation, oxygen and heat, which comprises adding, to the polymers, in particular to the polyolefins, an effective amount of these stabilizers. The present invention further relates to polymers, in particular polyolefins, which have been stabilized with respect to exposure to UV radiation or with respect to exposure to UV radiation, oxygen and heat, which comprise an effective amount of these polymer powders or, respectively, stabilizer mixtures, and to articles produced from these stabilized polymers, in particular polyolefins.

The present invention relates to the use, for stabilizing polymers, inparticular polyolefins, with respect to exposure to UV radiation, offine-particle polymer powders comprising at least one UV absorber.

The present invention further relates to stabilizer mixtures forstabilizing polymers with respect to exposure to UV radiation, oxygenand heat, which, inter alia, comprise these polymer powders, and to aprocess for stabilizing polymers, in particular polyolefins, withrespect to exposure to UV radiation, oxygen and heat, which comprisesadding, to the polymers, in particular to the polyolefins, an effectiveamount of these stabilizer mixtures.

The present invention further relates to polymers, in particularpolyolefins, which have been stabilized with respect to exposure to UVradiation or with respect to exposure to UV radiation, oxygen and heat,and which comprise an effective amount of these polymer powders or,respectively, stabilizer mixtures, and to articles produced from thesestabilized polymers, in particular polyolefins.

The incorporation of UV absorbers in order to stabilize polymers withrespect to damaging exposure to UV radiation is a very general practicein the plastics-processing industry. Important factors here forlonglasting protection are not only the long-term stability of the UVabsorbers but also the stable dispersion of these in the polymer. Thisdepends mainly on the compatibility of the UV absorber with the polymerused. If this is low, the consequence, in particular at the elevatedtemperatures encountered during processing, is very often undesiredmigration of the stabilizer to the polymer surface with resultantnon-uniform stabilization of the polymer composition.

It is an object of the present invention, therefore, to provideappropriate UV absorbers which are stable with respect to migration whenincorporated into polymers and therefore bring about uniformstabilization of the polymer composition.

We have found that this object is achieved by way of fine-particlepolymer powders comprising at least one UV absorber.

Stabilizer mixtures have also been found, which comprise

-   -   (a) at least one polymer powder which comprises at least one UV        absorber,

and at least one other component selected from the group consisting of:

-   -   (b) at least one compound selected from the group consisting of        organic phosphites, organic phosphines, and organic        phosphonites,    -   (c) at least one compound selected from the group consisting of        sterically hindered phenols,    -   (d) at least one compound selected from the group consisting of        sterically hindered amines,    -   (e) at least one compound selected from the group of the        chromanes, and    -   (f) at least one organic or inorganic salt selected from the        group consisting of zinc salts, calcium salts, magnesium salts,        cerium salts, iron salts and manganese salts.

The polymer powders comprising UV absorbers are usually obtainable viathe intermediate stage of a polymer dispersion obtained through emulsionpolymerization of a microemulsion, with a subsequent drying step. Thepreparation of colorant-containing polymer dispersions and ofcorresponding colorant-containing polymer powders is described in thespecifications WO 99/40123, WO 00/18846, EP 1 092 416 A2, and EP 1 191041 A2. In the last two of these specifications, colorants in thebroader sense includes UV absorbers. In the specifications EP 1 092 416A2 and EP 1 191 041 A2, polymers comprising these UV absorbers are usedto formulate cosmetic compositions.

The abovementioned specifications and the literature cited therein aretherefore expressly incorporated herein by way of reference in relationto the preparation of the polymer powders which comprise at least one UVabsorber and which are to be used according to the invention tostabilize polymers with respect to exposure to UV radiation. Particularspecifications incorporated are EP 1 092 416 A2 and EP 1 191 041 A2, thedescriptions in paragraphs [0006]-[0084] and [0111]-[0133], inparticular [0129]-[0133] being of relevance in the first of these, andthe descriptions in paragraphs [0006]-[0077] and [0100]-[0102] being ofrelevance in the second of these.

For the purposes of the present invention, the meaning of the expressionthat the polymer powders “comprise” the UV absorber(s) is that the UVabsorber(s) may either have homogeneous distribution in molecular ormicrocrystalline form in the polymer matrix (to which reference is alsomade by way of example in lines 25-29 on page 3 of the specification WO00/18846), or else has been completely or merely partially encapsulatedby the polymer matrix. (“UV absorber” is used hereinafter in thesingular even if according to the invention more than one UV absorbermay be present in the polymer powder.)

The sense of what has been said above is therefore that it is notessential that the UV absorber be (at least partially) soluble in thestarting monomers used to prepare the polymer dispersions. It merely hasto be wettable by the starting monomers or have been enclosed (at leastpartially) by the monomer droplets during the emulsion polymerization,and must have a suitable particle size distribution.

Clearly, chemical modification of the UV absorber via introduction ofsubstituents can be used to improve its wettability or solubility by thestarting monomers. For the most important case arising in industry,where the starting monomers have little or no polarity, the UV absorbermay, if necessary, be chemically modified using lipophilic radicals, asdescribed in paragraphs [0012]-[0015] of the specification EP 1 092 416A2.

UV absorbers which may be used in the polymer powders are:

4-aminobenzoic acid and its derivatives, in particular esters thereof,e.g. (ethoxylated)ethyl 4-aminobenzoate or2-ethylhexyl-4,4-dimethylaminobenzoic acid;

benzoates and salicylates, e.g. phenyl salicylate, 4-isopropyl-benzylsalicylate, 4-tert-butylphenyl salicylate, octylphenyl salicylate,benzoylresorcinol, bis(4-tert-butylbenzoyl)-resorcinol,dibenzoylresorcinol, 2,4-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl3,5-di-tert-butyl-4-hydroxybenzoate;

substituted acrylates, e.g. ethyl or isooctylα-cyano-β,β-diphenylacrylate (mainly 2-ethylhexylα-cyano-β,β-diphenylacrylate), methylα-methoxycarbonyl-β-phenylacrylate, methylα-methoxycarbonyl-β-(p-methoxyphenyl)acrylate, methyl or butylα-cyano-β-methyl-β-(p-methoxyphenyl)acrylate,N-(β-methoxycarbonyl-β-cyanovinyl)-2-methylindoline, octylp-methoxycinnamate, isopentyl 4-methoxycinnamate, urocanic acid and itssalts and esters;

2-hydroxybenzophenone derivatives, e.g. 4-hydroxy-, 4-methoxy-,4-octyloxy-, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-,4,2′,4′-trihydroxy-, 2′-hydroxy-4,4′-dimethoxy-2-hydroxybenzophenone,and also sodium 4-methoxy-2-hydroxybenzophenone-sulfonate;

esters of 4,4-diphenylbutadiene-1,1-dicarboxylic acid, e.g. thebis(2-ethylhexyl)ester;

2-phenylbenzimidazole-4-sulfonic acid, and also2-phenylbenzimidazole-5-sulfonic acid, and salts thereof;

derivatives of benzoxazoles;

derivatives of benzotriazoles and 2-(2′-hydroxyphenyl)benzotriazoles,e.g.2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-((1,1,3,3-tetramethyl-1-(trimethylsilyloxy)-disiloxanyl)propyl)phenol,2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-[2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole,2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,2-(2′-hydroxy-4′-octyloxyphenyl)benzotriazole,2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,2-[3′,5′-bis(α,α-dimethylbenzyl)-2′-hydroxyphenyl]benzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl]-5-chlorobenzotriazole,2-[3′-tert-butyl-5′-(2-(2-ethylhexyloxy)carbonylethyl)-2′-hydroxyphenyl]-5-chlorobenzotriazole,2[3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl]-5-chlorobenzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl]benzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl]benzotriazole,2-[3′-tert-butyl-5′-(2-(2-ethylhexyloxy)carbonylethyl)-2′-hydroxyphenyl]benzotriazole,2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenyl]benzotriazole,2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol],the fully esterified product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazolewith polyethylene glycol 300, [R—CH₂CH₂—COO(CH₂)₃—]₂, where R is3′-tert-butyl-4-hydroxy-5′-2H-benzotriazol-2-ylphenyl,2-[2′-hydroxy-3′-(α,α-dimethylbenzyl)-5′-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole,2-[2′-hydroxy-3′-(1,1,3,3-tetramethylbutyl)-5′-(α,α-dimethylbenzyl)phenyl]benzotriazole;

benzylidenecamphor and its derivatives as mentioned by way of example inDE-A 3 836 630, e.g. 3-benzylidenecamphor,3-(4′-methylbenzylidene)-d1-camphor;

α-(2-oxoborn-3-ylidene)toluene-4-sulfonic acid and its salts,N,N,N-trimethyl-4-(2-oxoborn-3-ylidenemethyl)anilinium methosulfate;

dibenzoylmethanes, e.g. 4-tert-butyl-4′-methoxydibenzoylmethane;

2,4,6-triaryltriazine compounds, e.g.2,4,6-tris{N-[4-(2-ethylhex-1-yl)oxycarbonylphenyl]amino}-1,3,5-triazine,4,4′-((6-(((tert-butyl)aminocarbonyl)phenylamino)-1,3,5-triazine-2,4-diyl)imino)bis(2′-ethylhexylbenzoate);and

2-(2-hydroxyphenyl)-1,3,5-triazines, e.g.2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2,4-bis-(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(4-methylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[4-(dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,2-[2-hydroxy-4(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine,2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine,2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine,2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine,2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine,2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]-phenyl}-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

Other suitable UV absorbers may be found in the publication CosmeticLegislation, Vol. 1, Cosmetic Products, European Commission 1999, pp.64-66, hereby incorporated herein by way of reference.

The polymer powders used which comprise UV absorbers preferably have apolymer particle size≦500 nm.

Whether or not use is made of the embodiment described above, it ispreferable to use polymer powders which comprise from 0.5 to 50% byweight of the at least one UV absorber, based on the weight of thepolymer matrix.

Preferred stabilizer mixtures comprising component (a) and one or moreof components (b) to (f) are those which comprise at least one polymerpowder (a) whose polymer particle size is ≦500 nm.

Whether or not use is made of the embodiment described above, otherpreferred stabilizer mixtures comprise at least one polymer powder(s)which comprises from 0.5 to 50% by weight of the at least one UVabosrber, based on the weight of the polymer matrix.

Component (b), which is a possible constituent in the stabilizermixtures of the invention, preferably comprises at least one organicphosphite, organic phosphine, or organic phosphonite selected from thegroup of the compounds of the formulae (VI) to (XV):

where

-   -   n′ is 2, 3 or 4;    -   p′ is 1 or 2;    -   q′ is 2 or 3;    -   r′ is an integer from 4 to 12;    -   y′ is 1, 2 or 3;    -   z′ is an integer from 1 to 6;    -   A′ for n′ equal to 2 is a C₂-C₁₈-alkylene group; a        C₂-C₁₂-alkylene group containing an oxygen atom or containing a        sulfur atom, or containing an NR′₄ group; a group of the        formula:

-   -   -   a group of the formula:

-   -   -   or        -   a phenylene group;        -   for n′ equal to 3 is a —C_(r′)H_(2r′-1)— group, where r′ is            as defined above; and        -   for n′ equal to 4 is a group of the formula

-   -   A″ for q′ equal to 2 or 3 is as defined for A′ for n′ equal to 2        or 3;    -   B′ is a single chemical bond; a —CH₂—, —CHR′₄—, or —CR′₁R′₄—        group; a sulfur atom, C₅-C₇-cycloalkylidene; cyclohexylidene        substituted with from one to four C₁-C₄-alkyl groups in the 3-,        4-, and/or 5-position;    -   B″ is C₁-C₃₀-alkylene, uninterrupted or interrupted by NH, by        N(C₁-C₂₄-alkyl), by P(C₁-C₂₄-alkyl), by oxygen, or by sulfur;        mono- or polyunsaturated C₁-C₃₀-alkylidene, uninterrupted or        interrupted by NH, by N(C₁-C₂₄-alkyl), by P(C₁-C₂₄-alkyl), by        oxygen, or by sulfur; C₅-C₇-cycloalkylidene, uninterrupted or        interrupted by NH, by N(C₁-C₂₄-alkyl), by P(C₁-C₂₄-alkyl), by        oxygen, or by sulfur; C₅-C₂₄-heteroarylene or C₆-C₂₄-arylene,        unsubstituted or substituted by C₁-C₂₄-alkyl, by        C₃-C₁₂-cycloalkyl, or by C₁-C₁₈-alkoxy;    -   D′ for p′ equal to 1 is a methyl group; and        -   for p′ equal to 2 is a —CH₂OCH₂— group;    -   E′ for y′ equal to 1 is C₁-C₂₄-alkyl; an —OR′₁ group; or        halogen;        -   for y′ equal to 2 is an —O-A″-O— group, where A″ is as            defined for A′ for n′ equal to 2; and        -   for y′ equal to 3 is an R′₄C(CH₂O—)₃ or N(CH₂CH₂O—)₃ group;    -   Q′ is a z′-valent radical of an alcohol or phenol, in each case        bonded to the phosphorus atom by way of an oxygen atom;    -   R′₁, R′₂ and R′₃ independently of one another, are hydrogen; a        —COOR′₄— or —CONR′₄R′₄ group; C₁-C₂₄-alkyl which contains an        oxygen atom or contains a sulfur atom, or contains an —NR′₄—        group; C₇-C₉-phenylalkyl; C₃-C₁₂-cycloalkyl; naphthyl or phenyl,        unsubstituted or substituted with halogen or with from one to        three C₁-C₂₄-alkyl, C₁-C₂₄-alkoxy or C₇-C₉-phenylalkyl groups;        or a group of the formula:

-   -   -   where m′ is an integer from 3 to 6;

    -   R′₄ is hydrogen; C₁-C₂₄-alkyl; C₃-C₁₂-cycloalkyl;        C₇-C₉-phenylalkyl;

    -   R′₅ and R′₆, independently of one another, are hydrogen;        C₁-C₆-alkyl; C₅-C₆-cycloalkyl;

    -   R′₇ and R′₈        -   for q′ equal to 2, independently of one another, are            C₁-C₄-alkyl or, together, a pentamethylene group;        -   for q′ equal to 3 are in each case a methyl group;

    -   R′₁₄ is hydrogen; C₁-C₉-alkyl; cyclohexyl;

    -   R′₁₅ is hydrogen; a methyl group;

    -   X′ and Y′ are a single chemical bond; an oxygen atom;

    -   Z′ is a single chemical bond, a methylene group; a —C(R′₁₆)₂—        group; a sulfur atom;

    -   R′₁₆ is C₁-C₆-alkyl;

    -   R′₁₇ and R′₁₈ independently of one another, are hydrogen;        C₁-C₂₄-alkyl, uninterrupted or interrupted by NH, by        N(C₁-C₂₄-alkyl), by oxygen, or by sulfur; C₇-C₉-phenylalkyl;        mono- or polyunsaturated C₂-C₂₄-alkenyl; C₂-C₂₄-alkynyl;        C₂-C₈-alkoxyalkyl; unsubstituted or substituted        C₃-C₁₂-cycloalkyl; unsubstituted or substituted        C₅-C₂₄-heteroaryl; unsubstituted or substituted C₆-C₂₀-aryl;        C₁-C₃₀-arylalkyl; C₂-C₂₄-alkoxy.

Component (b) particularly preferably comprises at least one organicphosphite, organic phosphine, or organic phosphonite selected from thegroup of the compounds of the formulae (VI), (VII), (X), and (XI), where

-   -   n′ is 2;    -   y′ is 1, 2 or 3;    -   A′ is a C₂-C₁₈-alkylene group; a p-phenylene group or a        p-biphenylene group;    -   E′ for y′ equal to 1 is C₁-C₁₈-alkyl; an —OR′₁ group; or        fluorine;        -   for y′ equal to 2 is a p-biphenylene group; and        -   for y′ equal to 3 is an N(CH₂CH₂O—)₃ group;    -   R′₁, R′₂ and R′₃, independently of one another, are        C₂-C₁₈-alkyl; C₇-C₉-phenylalkyl; cyclohexyl; phenyl,        unsubstituted or substituted with from one to three C₁-C₁₈-alkyl        groups;    -   R′₁₄ is hydrogen; C₁-C₉-alkyl;    -   R′₁₅ is hydrogen; a methyl group;    -   X′ is a single chemical bond;    -   Y′ is an oxygen atom;    -   Z′ is a single chemical bond; a —C(R′₁₆)₂— group;    -   R′₁₆ is C₁-C₄-alkyl.

Other particularly preferred organic phosphites or organic phosphonitesof component (b) are those selected from the group of compounds of theformulae (VI), (VII), (X), and (XI), where

-   -   n′ is 2;    -   y′ is 1 or 3;    -   A′ is a p-biphenylene group;    -   E′ for y′ equal to 1 is C₁-C₁₈-alkyl; fluorine;        -   for y′ equal to 3 is an N(CH₂CH₂O—)₃ group;    -   R′₁, R′₂, and R′₃, independently of one another, are        C₂-C₁₈-alkyl; phenyl substituted with from two to three        C₂-C₁₂-alkyl groups;    -   R′₁₄ is a methyl group or tert-butyl group;    -   R′₁₅ is hydrogen;    -   X′ is a single chemical bond;    -   Y′ is an oxygen atom;    -   Z′ is a single chemical bond; a methylene group; a —CH(CH₃)—        group.

Other particularly preferred organic phosphites of component (b) arethose of the formula (XVI)

where

-   -   R″₁ and R″₂, independently of one another, are hydrogen;        C₁-C₈-alkyl; cyclohexyl; phenyl;    -   R″₃ and R″₄, independently of one another, are hydrogen;        C₁-C₄-alkyl.

Examples of phosphites and phosphonites of component (b) are: triphenylphosphite; diphenyl alkyl phosphites; phenyl dialkyl phosphites;tris(nonylphenyl)phosphite (commercially available with the tradenameAlkanox® TNPP; Great Lakes Chemical Corp.); trilauryl phosphite;trioctadecyl phosphite; distearyl pentaerythritol diphosphite;tris(2,4-di-tert-butylphenyl)phosphite (commercially available with thetradename Alkanox® 240; Great Lakes Chemical Corp.); diisodecylpentaerythritol diphosphite; bis(2,4-di-tert-butylphenyl)pentaerythritoldiphosphite (commercially available with the tradename Alkanox® P24;Great Lakes Chemical Corp.);bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite;bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite;bis[2,4,6-tris-(tert-butyl)phenyl]pentaerythritol diphosphite;trisstearylsorbitol phosphite; tetrakis(2,4-di-tert-butylphenyl)4,4′-diphenylenediphosphonite (commercially available with the tradenameAlkanox® 24-44; Great Lakes Chemical Corp.);6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocin;6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyldibenzo[d,g]-1,3,2-dioxaphosphocin;bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite;bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite (commerciallyavailable with the tradename Irgafos® 38; Ciba Specialty Chemicals);bis(2,4-dicumylphenyl)pentaerythritol diphosphite,2,2′,2″-nitrilotriethyltris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite,2-ethylhexyl 3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diylphosphite.

Mention should in particular be made here of:tris(2,4-di-tert-butylphenyl)phosphite; tris(nonylphenyl)phosphite;6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyldibenzo-[d,g]-1,3,2-dioxaphosphocin;6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocin;bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite;bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite;bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite;bis(2,4-dicumylphenyl)pentaerythritol diphosphite;tetrakis(2,4-di-tert-butylphenyl) 4,4′-diphenylene diphosphonite; thetriphosphite of the formula (XVII)

and the diphosphite of the formula (XVIII)

Possible components (b) which should be emphasized here in particularare the organic phosphites and phosphonites: tris(nonylphenyl)phosphite;tris(2,4-di-tert-butylphenyl)phosphite;bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite;tetrakis(2,4-di-tert-butylphenyl) 4,4′-diphenylenediphosphonite; andbis(2,4-dicumylphenyl)pentaerythritol diphosphite.

The organic phosphites and phosphonites listed above for component (b)are compounds known per se, many of which are commercially available.

Sterically hindered phenols as possible component (c) of the stabilizermixtures of the invention preferably comply with the formula (XIX)

where

-   -   R₁′ is C₁-C₄-alkyl;    -   n″ is 1, 2, 3, or 4;    -   X″ is a methylene group; or a group of the formula (XX) or (XXI)

-   -   -   where Y″ is an oxygen atom; or an —NH— group;

    -   and where X″        -   for n″ equal to 1 is a group of the formula (XX) where Y″            has bonding to R₂′ and R₂′ is C₁-C₂₅-alkyl;        -   for n″ equal to 2 is a group of the formula (XX), where Y″            has bonding to R₂′ and R₂′ is a C₂-C₁₂-alkylene group; a            C₄-C₁₂-alkylene group containing one or more oxygen or            sulfur atoms; where if Y″ is an —NH— group, R₂′ is a single            chemical bond;        -   for n″ equal to 3 is a methylene group; a group of the            formula (XXI), where the ethylene group has bonding to R₂′            and R₂′ is a group of the formula (XXII)

-   -   -   for n″ equal to 4 is a group of the formula (XX), where Y″            has bonding to R₂ and R₂′ is a C₄-C₁₀-alkanetetrayl group.

Examples of linear and branched C₁-C₂₅-alkyl groups are methyl, ethyl,propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, 2-ethylbutyl,pentyl, 1-methylpentyl, isopentyl, neopentyl, tert-pentyl, hexyl,1,3-dimethylbutyl, 2-methylpentyl, heptyl, isoheptyl, 1-methylhexyl,1-ethylpentyl, octyl, 2-ethylhexyl, isooctyl, 1,1,3,3-tetramethylbutyl,1-methylheptyl, 3-methylheptyl, nonyl, isononyl,1,1,3,3-tetramethylpentyl, decyl, 1,1,3-trimethylhexyl, isodecyl,undecyl, dodecyl, 1-methylundecyl, 1,1,3,3,5,5-hexamethylhexyl,tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl,octadecyl, nonadecyl, eicosyl and doeicosyl (the terms isooctyl,isononyl, isodecyl, and isotridecyl used above being trivial names whichderive from the alcohols obtained by oxo synthesis—cf. in this respectUllmanns Encyklopädie der technischen Chemie, 4^(th) edition, Volume 7,pp. 215-217, and also Volume 11, pp. 435 and 436);

R₁′ is preferably a methyl group or tert-butyl group.

For n″ equal to 1, R₂′ is preferably a C₁-C₂₀-alkyl group, in particulara C₄-C₁₈-alkyl group. Particular definitions which should be emphasizedfor R₂′ are C₉-C₁₈-alkyl groups, and specifically here C₁₄-C₁₈-alkylgroups, e.g. octadecyl.

For n″ equal to 2, R₂′ is usually a C₂-C₁₀-alkylene group, preferably aC₂-C₈-alkylene group. R₂′ is in particular a C₄-C₈-alkylene group,particularly preferably a C₄-C₆-alkylene group, e.g. hexamethylene.Where appropriate here, the alkylene groups may also contain one or moreoxygen atoms or sulfur atoms.

Examples of linear or branched C₂-C₁₂-alkylene groups are ethylene,propylene, tetramethylene, pentamethylene, hexamethylene,heptamethylene, octamethylene, decamethylene, and dodecamethylene.

Examples of C₄-C₁₂-alkylene groups which contain one or more oxygenatoms or one or more sulfur atoms are —CH₂—O—CH₂CH₂—O—CH₂—,—CH₂—(O—CH₂CH₂)₂—O—CH₂—, —CH₂—(O—CH₂CH₂)₃—O—CH₂—,—CH₂—(O—CH₂CH₂)₄—O—CH₂—, and in particular —CH₂CH₂—O—CH₂CH₂—O—CH₂CH₂—,and —CH₂CH₂—S—CH₂CH₂—.

Examples of C₄-C₁₀-alkanetetrayl groups for R₂′, if n″ is equal to 4,are

preferably the pentaerythritol radical.

In accordance with the abovementioned preferences, preferred stericallyhindered phenols as possible component (c) are those where for n″ equalto 1 in the formula (XIX) the radical R₂′ is a C₁-C₂₀-alkyl group.

In accordance with the abovementioned preferences, other preferredsterically hindered phenols as possible component (c) are those wherefor n″ equal to 2 in the formula (XIX) the radical R₂′ is aC₂-C₆-alkylene group, a C₄-C₈-alkylene group which contains one or moreoxygen atoms or one or more sulfur atoms, or, in the event that Y″ is an—NH— group, a single chemical bond.

Other preferred sterically hindered phenols as possible component (c)are those where for n″ equal to 4 in the formula (XIX) the radical R₂′is one of the C₄-C₆-alkanetetrayl groups indicated above by way ofexample.

Other preferred sterically hindered phenols as possible component (c) inthe stabilizer mixtures of the invention are those where in the formula(XIX) R₁′ is a methyl group or tert-butyl group, n″ assumes a value of1, 2, or 4, and X″ is a group (XX), and Y″ is an oxygen atom or an —NH—group, where for

n″ equal to 1, R₂′ is a C₁₄-C₁₈-alkyl group,

n″ equal to 2, R₂′ is a C₄-C₆-alkylene group, or a C₄-C₆-alkylene groupcontaining one or more oxygen atoms or containing one or more sulfuratoms, and

n″ equal to 4, R₂′ is a C₄-C₆-alkanetetrayl group.

Sterically hindered phenols which are of interest as possible component(c) are those which have the formula (XIX) and which belong to thefollowing listed group:N,N′-hexamethylene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide](commercially available with the trademark Lowinox® HD-98; Great LakesChemical Corp.); octadecyl3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)propionate (commerciallyavailable with the trademark Anox™ PP18; Great Lakes Chemical Corp.);tetrakismethylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane(commercially available with the trademark Anox™ 20; Great LakesChemical Corp.); triethyleneglycolbis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate](commercially available with the trademark Lowinox® GP-45; Great LakesChemical Corp.); 2,2′-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (commerciallyavailable with the trademark Anox™ 70; Great Lakes Chemical Corp.);1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate (commerciallyavailable with the trademark Anox™ IC-14; Great Lakes Chemical Corp.);the compound of the formula

(commercially available with the trademark Irganox® 259; Ciba SpecialtyChemicals); the compound of the formula

(commercially available with the trademark Irganox® 3125; Ciba SpecialtyChemicals).

Other sterically hindered phenols preferred as possible component (c) inthe stabilizer mixtures of the invention are those which contain asterically hindered phenol group of the formula (I′) or (I′a)

where R′₁ and R′₂, independently of one another, are as defined above.

Compounds of the formulae (II′) and (II′a) are of particular interesthere.

Compounds of the formulae (II′) and (II′a) and compounds which containgroups of the formulae (I′) and (I′a) are described in thespecifications EP 162 523 A2 and EP 182 415 A2, which are expresslyincorporated herein by way of reference. The compounds indicated abovecan give complex and highly viscous products of hydrolysis and/orcondensation because the silyl radicals are hydrolyzable.

An example of the abovementioned compounds containing silyl groups isindicated below in the formula (II″):

The “compound” is composed of a mixture, composed of linear oligomerswhere R₁ is hydroxy and R₂ is hydrogen, and of cyclic oligomers whereeach of R₁ and R₂ is a single chemical bond, with an average molar massof 3 900 g/mol.

As mentioned above, the sterically hindered phenols as possiblecomponent (c) are known, and in some cases are also commerciallyavailable. Others among these compounds may moreover be prepared, forexample, as described in the specifications U.S. Pat. No. 3,330,859,U.S. Pat. No. 3,960,928, EP 162 523 A2, and EP 182 415 A2.

Sterically hindered amines may also be present as further possiblecomponent (d) in the stabilizer compositions of the invention. At leastone group of the formula (XXIII) or (XXIV)

is present in these compounds, where

-   -   G is hydrogen; a methyl group;    -   G₁ and G₂, independently of one another, are hydrogen; a methyl        group; or, together, an oxygen atom.

As possible component (d) in the stabilizer mixtures of the invention,use may be made of sterically hindered amines, preferably those selectedfrom the groups (a′) to (h′) of compounds listed below, and which haveat least one of the abovementioned groups of the formulae (XXIII) or(XXIV).

Group (a′): compounds of the formula (XXV):

where

-   -   n is an integer from 1 to 4;    -   G and G₁, independently of one another, are hydrogen or a methyl        group;    -   G₁₁ is hydrogen, oxygen (N-G₁₁ then forming a nitroxyl group),        hydroxy, an NO group (nitroso group), a —CH₂CN group,        C₁-C₁₈-alkyl, C₃-C₈-alkenyl, C₃-C₈-alkynyl, C₇-C₁₂-arylalkyl,        C₁-C₁₈-alkoxy, C₅-C₈-cycloalkoxy, C₇-C₉-phenylalkoxy,        C₁-C₈-alkanoyl, C₃-C₅-alkenoyl, C₁-C₁₈-alkanoyloxy, benzyloxy,        glycidyl; a —CH₂CH(OH)—Z group where Z is hydrogen, is methyl,        or is phenyl; preferably hydrogen, C₁-C₄-alkyl, allyl, benzyl,        acetyl or acryloyl;    -   G₁₂ for n equal to 1 is hydrogen, C₁-C₁₈-alkyl, containing no,        or one, or more than one, oxygen atom, cyanoethyl, benzyl,        glycidyl, a monovalent radical of an aliphatic, unsaturated or        aromatic, cycloaliphatic, or arylaliphatic carboxylic acid,        carbamic acid, or phosphorus-containing acid, or a monovalent        silyl radical, preferably a radical of an aliphatic carboxylic        acid having from 2 to 18 carbon atoms of a cycloaliphatic        carboxylic acid having from 7 to 15 carbon atoms, of an        α,β-unsaturated carboxylic acid having 3 to 5 carbon atoms, of        an aromatic carboxylic acid having from 7 to 15 carbon atoms,        where the aliphatic, cycloaliphatic, or aromatic moiety of these        carboxylic acids has no substitution or has substitution with        from one to 3 —COOZ₁₂ groups, and Z₁₂ is hydrogen, C₁-C₂₀-alkyl,        C₃-C₁₂-alkenyl, C₅-C₇-cycloalkyl, phenyl, or benzyl;        -   for n equal to 2 is C₂-C₁₂-alkylene, C₄-C₁₂-alkenylene, a            xylylene group, a divalent radical of an aliphatic,            cycloaliphatic, arylaliphatic, or aromatic dicarboxylic            acid, dicarbamic acid, or phosphorus-containing acid, or a            divalent silyl radical, preferably a radical of an aliphatic            dicarboxylic acid having from 2 to 36 carbon atoms, of a            cycloaliphatic or aromatic dicarboxylic acid having from 8            to 14 carbon atoms, of an aliphatic, cycloaliphatic or            aromatic dicarbamic acid having from 8 to 14 carbon atoms,            or where the aliphatic, cycloaliphatic, or aromatic moiety            of these carboxylic acids has no substitution or            substitution with one or two —COOZ₁₂ groups, and Z₁₂ is as            defined above;        -   for n equal to 3 is a trivalent radical of an aliphatic,            cycloaliphatic, or aromatic tricarboxylic acid, where the            aliphatic, cycloaliphatic, or aromatic moiety of this            carboxylic acid has no substitution or has substitution with            a —COOZ₁₂ group, and Z₁₂ is as defined above, or of an            aromatic tricarbamic acid, or of a phosphorus-containing            acid, or is a trivalent silyl radical; and        -   for n equal to 4 is a tetravalent radical of an aliphatic,            cycloaliphatic, or aromatic tetracarboxylic acid.

Examples of C₁-C₁₂-alkyl groups are: methyl, ethyl, n-propyl, n-butyl,sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl,n-undecyl and n-dodecyl.

Examples of C₁-C₁₈-alkyl groups for G₁₁ and G₁₂, in addition to theabovementioned groups, are: n-tridecyl, n-tetradecyl, n-hexadecyl, andn-octadecyl.

Examples of C₃-C₈-alkenyl groups for G₁₁ are: 1-propenyl, allyl,methallyl, 2-butenyl, 2-pentenyl, 2-hexenyl, 2-octenyl, and4-tert-butyl-2-butenyl.

Propargyl is preferably used as C₃-C₈-alkynyl group for G₁₁.

A particular group which may be used as C₇-C₁₂-arylalkyl group for G₁₁is phenylethyl, or preferably benzyl.

Examples of C₁-C₈-alkanoyl groups for G₁₁ are: formyl, propionyl,butyryl, octanoyl, and in particular acetyl and, in the case of aC₃-C₅-alkanoyl group, preferably acryloyl.

Examples of monovalent carboxylic acid radicals for G₁₂ derive fromacetic acid, caproic acid (hexanoic acid), stearic acid (octadecanoicacid), acrylic acid, methacrylic acid, benzoic acid, andβ-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid.

Examples of monovalent silyl radicals for G₁₂ are: a radical of theformula —(C_(j)H_(2j))—Si(Z′)₂Z″, where j is an integer from 2 to 5 andZ′ and Z″, independently of one another, are a C₁-C₄-alkyl group orC₁-C₄-alkoxyl group.

Examples of bivalent dicarboxylic acid radicals for G₁₂ derive frommalonic acid, succinic acid, glutaric acid, adipic acid, suberic acid(octanedioic acid), sebacic acid, maleic acid, itaconic acid(methylenesuccinic acid), phthalic acid, dibutylmalonic acid,dibenzylmalonic acid, butyl(3,5-di-tert-butyl-4-hydroxybenzyl)malonicacid, and bicycloheptenedicarboxylic acid.

Examples of trivalent tricarboxylic acid radicals for G₁₂ derive fromtrimellitic acid, citric acid, and nitrilotriacetic acid.

Examples of tetravalent tetracarboxylic acid radicals for G₁₂ derivefrom butane-1,2,3,4-tetracarboxylic acid and pyromellitic acid(1,2,4,5-benzenetetracarboxylic acid).

Examples of divalent dicarbamic acid radicals for G₁₂ derive fromhexamethylenedicarbamic acid and 2,4-toluenedicarbamic acid.

Preference is given to compounds of the formula (XXV) where G ishydrogen, G₁₁ is hydrogen or methyl, G₁₂ is a diacyl radical of analiphatic dicarboxylic acid having from 4 to 12 carbon atoms, and n is2.

Particular examples of polyalkylpiperidines of the formula (XXV) are:

-   1) 4-hydroxy-2,2,6,6-tetramethylpiperidine;-   2) 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine;-   3) 1-benzyl-4-hydroxy-2,2,6,6-tetramethylpiperidine;-   4)    1-(4-tert-butyl-2-butenyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine;-   5) 4-stearyloxy-2,2,6,6-tetramethylpiperidine;-   6) 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine;-   7) 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine;-   8) 1,2,2,6,6-pentamethylpiperidin-4-yl    β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate;-   9) bis(1-benzyl-2,2,6,6-tetramethylpiperidin-4-yl)maleate;-   10) bis(2,2,6,6-tetramethylpiperidin-4-yl)succinate;-   11) bis(2,2,6,6-tetramethylpiperidin-4-yl)glutarate;-   12) bis(2,2,6,6-tetramethylpiperidin-4-yl)adipate;-   13) bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate;-   14) bis(1,2,2,6,6-pentamethylpiperidin-4-yl)sebacate;-   15) bis(1,2,3,6-tetramethyl-2,6-diethylpiperidin-4-yl)sebacate;-   16) bis(1-allyl-2,2,6,6-tetramethylpiperidin-4-yl)phthalate;-   17) 1-hydroxy-4-β-cyanoethyloxy-2,2,6,6-tetramethylpiperidine;-   18) 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl acetate;-   19) tris(2,2,6,6-tetramethylpiperidin-4-yl)trimellitate;-   20) 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine;-   21) bis(2,2,6,6-tetramethylpiperidin-4-yl)diethylmalonate;-   22) bis(1,2,2,6,6-pentamethylpiperidin-4-yl)dibutylmalonate;-   23)    bis(1,2,2,6,6-pentamethylpiperidin-4-yl)n-butyl(3,5-di-tert-butyl-4-hydroxybenzyl)malonate;-   24) bis(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate;-   25) bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate;-   26)    hexane-1′,6′-bis(4-carbamoyloxy-1-n-butyl-2,2,6,6-tetramethylpiperidine);-   27)    toluene-2′,4′-bis(4-carbamoyloxy-1-n-propyl-2,2,6,6-tetramethylpiperidine);-   28) dimethylbis(2,2,6,6-tetramethylpiperidin-4-oxy)silane;-   29) phenyltris(2,2,6,6-tetramethylpiperidin-4-oxy)silane;-   30) tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl)phosphite;-   31) tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl)phosphate;-   32) bis(1,2,2,6,6-pentamethylpiperidin-4-yl)phenylphosphonate;-   33) 4-hydroxy-1,2,2,6,6-pentamethylpiperidine;-   34) 4-hydroxy-N-hydroxyethyl-2,2,6,6-tetramethylpiperidine;-   35) 4-hydroxy-N-(2-hydroxypropyl)-2,2,6,6-tetramethylpiperidine;-   36) 1-glycidyl-4-hydroxy-2,2,6,6-tetramethylpiperidine;-   37) 4-benzoyl-2,2,6,6-tetramethylpiperidine;-   38) bis(1,2,2,6,6-pentamethylpiperidinyl)    2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate;-   39) bis(1-octyloxy-2,2,6,6-tetramethylpiperidinyl)succinate.

Group (b′): compounds of the formula (XXVI):

where

-   -   n is 1 or 2;    -   G, G₁, and G₁₁ are as defined under group (a′);    -   G₁₃ is hydrogen, C₁-C₁₂-alkyl, C₂-C₅-hydroxyalkyl,        C₅-C₇-cycloalkyl, C₇-C₈-arylalkyl, formyl, C₂-C₁₈-alkanoyl,        C₃-C₅-alkenoyl, benzoyl, or a group of the formula

-   -   G₁₄ for n equal to 1 is hydrogen, C₁-C₁₅-alkyl, C₃-C₈-alkenyl,        C₅-C₇-cycloalkyl, hydroxy-, cyano-, alkoxycarbonyl-, or        carbamoyl-substituted C₁-C₄-alkyl, or glycidyl, or a group of        the formula —CH₂—CH(OH)—Z or of the formula —CONH—Z, where Z is        hydrogen, methyl, or phenyl, or, for the non-alkanoyl meanings        of G₁₃, alkenoyl or benzoyl, or where G₁₃ and G₁₄ together form        a divalent radical of an aliphatic, cycloaliphatic or aromatic        1,3-dicarboxylic acid;        -   for n equal to 2 is C₂-C₁₂-alkylene, C₆-C₁₂-arylene, a            xylylene group, a group of the formula —CH₂—CH(OH)—CH₂—, or            a group of the formula —CH₂—CH(OH)—CH₂—O-D-O, where D is            C₂-C₁₀-alkylene, C₆-C₁₀-arylene, or C₆-C₁₂-cycloalkylene; a            1-oxo-(C₂-C₁₂)-alkylene group, a divalent radical of an            aliphatic, cycloaliphatic, or aromatic dicarboxylic or            dicarbamic acid, or —CO—; or where G₁₃ and G₁₄ on the            4-nitrogen atom of the two piperidinyl radicals together            form a radical of the formula

Possible C₁-C₁₂-alkyl or C₁-C₁₈-alkyl groups were described by way ofexample above in the group (a′).

As C₅-C₇-cycloalkyl, use is preferably made of cyclohexyl.

As arylalkyl for G₁₃, use may be made of phenylethyl, preferably benzyl.

As C₂-C₅-hydroxyalkyl for G₁₃, use may be made of 2-hydroxyethyl and2-hydroxypropyl, for example.

Examples of C₂-C₁₈-alkanoyl for G₁₃ are: propionyl, butyryl, octanoyl,dodecanoyl, hexadecanoyl, and octadecanoyl. Mention should in particularbe made of acetyl, and acryloyl is preferred if G₁₃ is C₃-C₅-alkenoyl.

Examples of C₂-C₈-alkenyl for G₁₄ are: allyl, methallyl, 2-butenyl,2-pentenyl, 2-hexenyl, and 2-octenyl.

Examples of hydroxy-, cyano-, alkoxycarbonyl-, or carbamoyl-substitutedC₁-C₄-alkyl are: 2-hydroxyethyl, 2-hydroxypropyl, 2-cyanoethyl,methoxycarbonylmethyl, 2-ethoxycarbonylethyl, 2-aminocarbonylpropyl, and2-(dimethylaminocarbonyl)ethyl.

Examples of C₂-C₁₂-alkylene are: ethylene, propylene,2,2-dimethylpropylene, tetramethylene, hexamethylene, octamethylene,decamethylene, and dodecamethylene.

Examples of C₆-C₁₅-arylene are: o-, m-, or p-phenylene, 1,4-naphthylene,and 4,4′-diphenylene.

As C₆-C₁₂-cycloalkylene, use may in particular be made of cyclohexylene.

Preferred compounds of the formula (XXVI) are those where n is 1 or 2and G is hydrogen, G₁₁ is hydrogen or methyl, G₁₃ is hydrogen, formyl,C₁-C₁₂-alkyl, or a group of the formula

and

-   -   G₁₄ for n equal to 1 is hydrogen or C₁-C₁₂-alkyl, and        -   for n equal to 2 is C₂-C₈-alkylene, or a            1-oxo-(C₂-C₈)-alkylene group.

Examples of polyalkylpiperidines of the formula (XXVI) are inparticular:

-   1)    N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diamine;-   2)    N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diacetamide;-   3) bis(2,2,6,6-tetramethylpiperidin-4-yl)amine;-   4) 4-benzoylamino-2,2,6,6-tetramethylpiperidine;-   5)    N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N′-dibutyladipamide;-   6)    N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N′-dicyclohexyl-2-hydroxypropylene-1,3-diamine;-   7) N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-p-xylylenediamine;-   8) N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)succinamide;-   9)    bis(2,2,2,6,6-tetramethylpiperidin-4-yl)N-(2,2,6,6-tetramethylpiperidin-4-yl)-β-aminodipropionate;-   10) a compound of the formula:

-   11) 4-[bis(2-hydroxyethyl)amino]-1,2,2,6,6-pentamethylpiperidine;-   12)    4-(3-methyl-4-hydroxy-5-tert-butylbenzamido)-2,2,6,6-tetramethylpiperidine;-   13) 4-methacrylamido-1,2,2,6,6-pentamethylpiperidine;-   14)    N,N′-bisformylbis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diamine    (commercially available with the trademark Uvinul® 4050 H; BASF    Aktiengesellschaft);-   15)    N,N′-bisformylbis(1,2,2,6,6-pentamethylpiperidin-4-yl)hexamethylene-1,6-diamine;-   16) a compound of the formula

-    (commercially available with the trademark Uvinul® 4049 H; BASF    Aktiengesellschaft);-   17) a compound of the formula

group (c′): compounds of the formula (XXVII):

where

-   -   n is 1 or 2;    -   G, G₁, and G₁₁ are as defined under group (a′);    -   G₁₅ for n equal to 1 is C₂-C₈-alkylene, C₂-C₈-hydroxyalkylene,        or C₄-C₂₂-acyloxyalkylene, and        -   for n equal to 2 is a (CH₂)₂C(CH₂—)₂ group.

Examples of C₂-C₈-alkylene or C₂-C₈-hydroxyalkylene for G₁₅ are:ethylene, 1-methylethylene, propylene, 2-ethylpropylene, and2-ethyl-2-hydroxymethylpropylene.

As an example of C₄-C₂₂-acyloxyalkylene for G₁₅, mention may be made of2-ethyl-2-acetoxymethylpropylene.

Examples of polyalkylpiperidines of the formula (XXVII) are inparticular:

-   1) 9-aza-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]undecane;-   2) 9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro[5.5]undecane;-   3) 8-aza-2,7,7,8,9,9-hexamethyl-1,4-dioxaspiro[4.5]decane;-   4)    9-aza-3-hydroxymethyl-3-ethyl-8,8,9,10,10-pentamethyl-1,5-dioxaspiro[5.5]undecane;-   5)    9-aza-3-ethyl-3-acetoxymethyl-9-acetyl-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]undecane;-   6)    2,2,6,6-tetramethylpiperidin-4-spiro-2′-(1′,3′-dioxane)-5′-spiro-5″-(1″,3″-dioxane)-2″-spiro-4″′-(2″′,2″′,6″′,6″′-tetramethylpiperidine).

Group (d′): compounds of the formulae (XXVIIIA), (XXVIIIB), andpreferably (XXVIIIC):

where

-   -   n is 1 or 2;    -   G, G₁, and G₁₁ are as defined under group (a′);    -   G₁₆ is hydrogen, C₁-C₁₂-alkyl, allyl, benzyl, glycidyl, or        C₂-C₆-alkoxyalkyl;    -   G₁₇ for n equal to 1 is hydrogen, C₁-C₁₂-alkyl, C₃-C₅-alkenyl,        C₇-C₉-arylalkyl, C₅-C₇-cycloalkyl, C₂-C₄-hydroxyalkyl,        C₂-C₆-alkoxyalkyl, C₆-C₁₀-aryl, glycidyl, or a group of the        formula —(CH₂)_(p)—COO-Q or —(CH₂)_(p)—O—CO-Q, where p is 1 or 2        and Q is C₁-C₄-alkyl or phenyl, and        -   for n equal to 2 is C₂-C₁₂-alkylene, C₄-C₁₂-alkenylene,            C₆-C₁₂-arylene, or a group of the formula:        -   —CH₂—CH(OH)—CH₂—O-D-O—CH₂—CH(OH)—CH₂—,        -   D being C₂-C₁₀-alkylene, C₆-C₁₅-arylene, or            C₆-C₁₂-cycloalkylene, or is a group of the formula:        -   —CH₂CH(OZ′)CH₂—OCH₂—CH(OZ′)CH₂—OCH₂—CH(OZ′)CH₂—,        -   Z′ being hydrogen, C₁-C₁₈-alkyl, allyl, benzyl,            C₂-C₁₂-alkanoyl, or benzoyl;    -   T₁ and T₂, independently of one another, are hydrogen,        unsubstituted or halogen- or C₁-C₄-alkyl-substituted        C₁-C₁₆-alkyl, unsubstituted or halogen- or        C₁-C₄-alkyl-substituted C₆-C₁₀-aryl, unsubstituted or halogen-        or C₁-C₄-alkyl-substituted C₇-C₉-arylalkyl; or T₁ and T₂        together with the carbon atom to which they are bonded form a        C₅-C₁₄ cycloalkane ring.

Examples of C₁-C₁₂-alkyl are: methyl, ethyl, n-propyl, n-butyl,sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl,n-undecyl, and n-dodecyl.

Examples of C₁-C₁₈-alkyl supplementary to the C₁-C₁₂-alkyl radicalslisted by way of example above are: n-tridecyl, n-tetradecyl,n-hexadecyl, and n-octadecyl.

Examples of C₂-C₆-alkoxyalkyl are: methoxymethyl, ethoxymethyl,propoxymethyl, tert-butoxymethyl, ethoxyethyl, ethoxypropyl,n-butoxyethyl, tert-butoxyethyl, isopropoxyethyl, and propoxypropyl.

Examples of C₃-C₅-alkenyl for G₁₇ are: 1-propenyl, allyl, methallyl,2-butenyl, and 2-pentenyl.

Examples of C₇-C₉-arylalkyl for G₁₇, T₁, and T₂ are: phenylethyl,preferably benzyl.

Examples of the case where T₁ and T₂ together with the carbon atom towhich they are bonded form cycloalkane rings are:

-   -   cyclopentane, cyclohexane, cyclooctane, and cyclododecane.

Examples of C₂-C₄-hydroxyalkyl for G₁₇ are: 2-hydroxyethyl,2-hydroxypropyl, 2-hydroxybutyl, and 4-hydroxybutyl.

Examples of C₆-C₁₀-aryl for G₁₇, T₁, and T₂ are: unsubstituted orhalogen- or C₁-C₄-alkyl-substituted phenyl, and unsubstituted orhalogen- or C₁-C₄-alkyl-substituted α- or β-naphthyl.

Examples of C₂-C₁₂-alkylene for G₁₇ are: ethylene, propylene,2,2-dimethylpropylene, tetramethylene, hexamethylene, octamethylene,decamethylene, and dodecamethylenes.

Examples of C₄-C₁₂-alkenylene for G₁₇ are: 2-butenylene, 2-pentenylene,and 3-hexenylene.

Examples of C₆-C₁₂-arylene for G₁₇ are: o-, m-, and p-phenylene,1,4-naphthylene, and 4,4′-diphenylene.

Examples of C₂-C₁₂-alkanoyl for Z are: propionyl, butyryl, octanoyl, anddodecanoyl, preferably acetyl.

Examples of C₂-C₁₀-alkylene, C₆-C₁₅-arylene, and C₆-C₁₂-cycloalkylenefor D are described under group (b′).

Examples of polyalkylpiperidines of the formulae (XXVIIIA), (XXVIIIB),and (XXVIIIC) are in particular:

-   1)    3-benzyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione;-   2)    3-n-octyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione;-   3)    3-allyl-1,3,8-triaza-1,7,7,9,9-pentamethylspiro[4.5]decane-2,4-dione;-   4)    3-glycidyl-1,3,8-triaza-7,7,8,9,9-pentamethylspiro[4.5]-decane-2,4-dione;-   5) 1,3,7,7,8,9,9-heptamethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione;-   6)    2-isopropyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro-[4.5]decane;-   7)    2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro-[4.5]decane;-   8)    2,2-dibutyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro-[4.5]decane;-   9)    2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxodispiro-[5.1.11.2]heneicosane;-   10)    2-butyl-7,7,9,9-tetramethyl-1-oxa-4,8-diaza-3-oxospiro-[4.5]decane;    and preferably-   11)    8-acetyl-3-dodecyl-1,3,8-triaza-7,7,9,9-tetramethyl-spiro[4.5]decane-2,4-dione;    and compounds of the following formulae:

Group (e′): compounds of the formula (XXIX):

where

-   -   n is 1 or 2;    -   G₁₈ is a group of the formula:

-   -   -   where G and G₁₁ are as defined under group (a′);        -   G₁ and G₂, independently of one another, are hydrogen, or            methyl, or together with the carbon atom to which they are            bonded are a carbonyl group;        -   E is oxygen or an —NG₁₃- group;        -   A is C₂-C₆-alkylene or a —(CH₂)₃—O— group;        -   x is 0 or 1;        -   G₁₃ is hydrogen, C₁-C₁₂-alkyl, C₂-C₅-hydroxyalkyl,            C₅-C₇-Cycloalkyl;

    -   G₁₉ is as defined for G₁₈ or is one of the following groups:        —NG₂₁G₂₂, —OG₂₃, —NHCH₂0G₂₃, or —N(CH₂0G₂₃)₂;

    -   G₂₀ for n equal to 1 is as defined for G₁₈ or G₁₉,        -   for n equal to 2 is an -E-B-E- group, where B is a            C₂-C₈-alkylene, uninterrupted or interrupted by one or two            —N(G₂₁) groups;

    -   G₂₁ is C₁-C₁₂-alkyl, cyclohexyl, benzyl, C₁-C₄-hydroxyalkyl, a        group of the following formula:

-   -   -   or a group of the following formula:

-   -   G₂₂ is C₁-C₁₂-alkyl, cyclohexyl, benzyl, C₁-C₄-hydroxyalkyl;        -   or G₂₁ and G₂₂ in the —NG₂₁G₂₂ group together form a            C₄-C₅-alkylene group or a C₄-C₅-oxyalkylene group, or a            group of the formula:

-   -   G₂₃ is hydrogen, C₁-C₁₂-alkyl, phenyl.

Examples of C₁-C₁₂-alkyl are: methyl, ethyl, n-propyl, n-butyl,sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl,n-undecyl, and n-dodecyl.

Examples of C₁-C₄-hydroxyalkyl are: 2-hydroxyethyl, 2-hydroxypropyl,3-hydroxypropyl, 2-hydroxybutyl, and 4-hydroxybutyl.

Examples of C₂-C₆-alkylene for A are: ethylene, propylene,2,2-dimethylpropylene, tetramethylene, and hexamethylene.

If G₂₁ and G₂₂ together form C₄-C₅-alkylene or C₄-C₅-oxyalkylene,mention should be made of: tetramethylene, pentamethylene, and3-oxapentamethylene.

Examples of polyalkylpiperidines of the formula (XXIX) are inparticular:

R—NH—(CH₂)₃—N(R)—(CH₂)₂—N(R)—(CH₂)₃—NH—R (XXIX)-6, where R is

R—NH—(CH₂)₃—N(R)—(CH₂)₂—N(R)—(CH₂)₃—NH—R (XXIX)-7, where R is

R—N(CH₃)—(CH₂)₃—N(R)—(CH₂)₂—N(R)—(CH₂)₃—N(CH₃)—R (XXIX)-8, where R is

Group (f′): oligomers or polymeric compounds whose repeat units contain2,2,6,6-tetramethylpiperidine radicals, in particular polyesters,polyethers, polyamides, polyamines, polyurethanes, polyureas,polyaminotriazines, poly(meth)acrylates, and poly(meth)acrylamides, andalso copolymers of these.

Examples of these 2,2,6,6-polyalkylpiperidines are determined by thefollowing formulae, where m is a number from 2 to 200:

where R is a

radical and each of m′ and m″ is a whole number from 0 to 200, with theproviso that m′+m″=m.

Other examples of polymeric compounds of the group (f′) are:

-   -   the reaction products of compounds of the formula (XXXI)

-   -   with epichlorohydrin;    -   polyesters which are obtained by reacting        butane-1,2,3,4-tetracarboxylic acid with dihydric alcohols of        the formula (XXXII):

-   -   and whose terminal carboxy group derived from the        tetracarboxylic acid has been esterified with        2,2,6,6-tetramethyl-4-hydroxypiperidine;    -   compounds of the formula (XXXIII):

-   -   where about one third of the radicals R are ethyl and the        remainder of the radicals R are a radical of the formula

-   -   and m is a number from 2 to 200;    -   copolymers whose repeat units derive firstly from        α-methylstyrene

-   -   and secondly from maleimide derivatives of the formulae

-   -   copolymers whose repeat units derive firstly from C₁₈-C₂₈        α-olefins or from mixtures of these olefins and secondly from        maleimide derivatives of the formula

-   -   By way of example here, mention should be made of the        commercially available product Uvinul® 5050 H (hydrogen only on        the 1-nitrogen of the piperidine ring; BASF Aktiengesellschaft).

Group (g′): compounds of the formula (XXXIV):

where

-   -   n is 1 or 2;    -   G and G₁₁ are as defined under group (a′), and    -   G₁₄ is as defined under group (b′), but neither a —CONH—Z group        nor a —CH₂CH(OH)—CH₂—O-D-O group.

Examples of compounds of the formula (XXXIV) are:

Group (h′): compounds of the formula (XXXV):

where:

-   -   R₁ is C₁-C₁₀-alkyl, unsubstituted or C₁-C₄-alkyl-substituted        C₅-C₁₂-cycloalkyl, unsubstituted or C₁-C₁₀-alkyl-substituted        phenyl;    -   R₂ is C₃-C₁₀-alkylene;    -   R₃ is hydrogen, C₁-C₈-alkyl, —O., —CH₂CN, C₃-C₆-alkenyl, or is        C₇-C₉-phenylalkyl, unsubstituted or with C₁-C₄-alkyl        substitution of the phenyl radical, or is C₁-C₈-acyl, an —OR′₃        group, with hydrogen or C₁-C₁₀-alkyl as R′₃, and    -   n is a number from 1 to 50.

Particularly important compounds for the purposes of the presentinvention are those which belong to the group (d) of the stericallyhindered amines and have been selected from: Uvinul® 4049 H (BASFAktiengesellschaft); Uvinul® 4050 H (BASF Aktiengesellschaft); Uvinul®5050 H (BASF Aktiengesellschaft); Tinuvin®123 (Ciba SpecialtyChemicals); Tinuvin®144 (Ciba Specialty Chemicals); Lowilite® 76 (GreatLakes Chemical Corporation); Lowilite® 62 (Great Lakes ChemicalCorporation); Lowilite® 94 (Great Lakes Chemical Corporation);Chimassorb® 119 (Ciba Specialty Chemicals); Cysorb® UV 3529 (Cytec);Cyasorb® UV 3346 (Cytec); the compound of the formula (XXXV)-1:

polymethylpropyl-3-oxy-[4-(2,2,6,6-tetramethyl)piperidinyl]-siloxane,commercially available with the trademark UVASIL® 299 (Great LakesChemical Corporation);polymethylpropyl-3-oxy-[4-(1,2,2,6,6-pentamethyl)piperidinyl]siloxane.

The compounds of the group (d) of the sterically hindered amines usedaccording to the invention have an average molecular weight M_(n) offrom 500 to 10,000, in particular from 1,000 to 10,000.

As possible component (e), the stabilizer mixtures may comprise at leastone compound selected from the group of the chromanes. These compoundspreferably have the formula (XXV)

where

-   -   R′₁₉ is hydrogen; C₁-C₂₄-alkyl; C₃-C₁₂-cycloalkyl; mono- or        polyunsaturated C₂-C₂₄-alkenyl; and    -   R′₂₀, R′₂₁, R′₂₂, and R′₂₃, independently of one another, are        hydrogen; C₁-C₂₄-alkyl; C₃-C₁₂-cycloalkyl; mono- or        polyunsaturated C₂-C₂₄-alkenyl; COOR′₁₉ carboxy groups;        —CH(COOR′₁₉)—CH₂—COOR′₁₉ succinyl groups.

Possible C₁₋₂₄-alkyl, C₃₋₁₂-cycloalkyl, and C₁₋₂₄-alkenyl radicals havebeen listed at an earlier stage above by way of example. Mention may bemade again here of the following:

For C₁-C₂₄-alkyl groups: methyl, ethyl, propyl, isopropyl, butyl,isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl,tert-pentyl, hexyl, 2-methylpentyl, heptyl, 1-ethylpentyl, octyl,2-ethylhexyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl,dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl,heptadecyl and octadecyl (the above terms isooctyl, isononyl, isodecyl,and isotridecyl being trivial names deriving from the alcohols obtainedby the oxo synthesis—cf. in this respect Ullmanns Encyklopädie dertechnischen Chemie, 4^(th) edition, Volume 7, pp. 215 to 217, and alsoVolume 11, pp. 435 and 436);

For unsubstituted or substituted C₃-C₁₂-cycloalkyl groups, cycloheptyl,cyclooctyl, cyclohexyl, cyclopentyl, methylcyclohexyl, and itsappropriate isomers;

For C₂-C₂₄-alkenyl groups: vinyl, 1- and 2-propenyl, 1-, 2-, and3-butenyl, 1-, 2-, 3-, and 4-pentenyl, 1-, 2-, 3-, 4- and 5-hexenyl.

Particularly preferred compounds of component (e) are2,5,7,8-tetramethyl-2-(4′,8′,12′-trimethyltridecyl)chroman-6-ol(α-tocopherol),

-   -   2,5,8-trimethyl-2-(4′,8′,12′-trimethyltridecyl)chroman-6-ol(β-tocopherol),    -   2,7,8-trimethyl-2-(4′,8′,12′-trimethyltridecyl)chroman-6-ol(γ-tocopherol),    -   2,8-dimethyl-2-(4′,8′,12′-trimethyltridecyl)chroman-6-ol(δ-tocopherol),    -   3,4-dihydro-2,2,5,7,8-pentamethyl-2H-1-benzopyran-6-ol, and    -   6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox).

As possible component (f), the stabilizer mixtures may comprise at leastone organic or inorganic salt selected from the group consisting of zincsalts, calcium salts, magnesium salts, cerium salts, iron salts, andmanganese salts.

In the case of the cerium salts, iron salts, and manganese salts, theoxidation state +2 is of importance for iron and manganese, theoxidation state +3 is of importance for cerium.

Preferred organic salts of zinc, calcium, magnesium, iron(II), andmanganese(II) have the formula Me(An)₂, and preferred organic salts ofcerium(III) have the formula Ce(An)₃, where Me is zinc, calcium,magnesium, iron(II), or manganese(II), and An is an anion of an organicacid or of an enol. The acid may be linear or branched, saturated orunsaturated, aliphatic, aromatic, araliphatic, or cycloaliphatic, andmay be unsubstituted or else may have substitution by hydroxy groups orby alkoxyl groups. The acid preferably contains from 1 to 24 carbonatoms. Examples of these organic acids are sulfonic acids, sulfinicacids, phosphonic acids, and phosphinic acids, and preferably carboxylicacids.

Examples of carboxylic acids of this type are formic, acetic, propionic,butyric, isobutyric, caproic, 2-ethylcaproic, caprylic, capric, lauric,palmitic, stearic, behenic, oleic, lactic, ricinoleic,2-ethoxypropionic, benzoic, salicylic, 4-butylbenzoic, 2-, 3-, or4-toluic, 4-dodecylbenzoic, phenylacetic, naphthylacetic,cyclohexanecarboxylic, 4-butylcyclohexanecarboxylic, andcyclohexylacetic acid. The carboxylic acid may also be a technicalmixture of carboxylic acids, for example of fatty acids or of alkylatedbenzoic acids.

Examples of organic acids which contain sulfur or contain phosphorus aremethanesulfonic, ethanesulfonic, dodecanesulfonic, benzenesulfonic,toluenesulfonic, 4-nonylbenzenesulfonic, benzenesulfinic, andnaphthalenesulfonic acid, dodecanesulfinic, benzenesulfinic, andnaphthalenesulfinic acid, butylphosphonic acid, phenylphosphonic acid,and monoalkyl esters thereof, and diphenylphosphinic acid.

If An is an enol anion, it is preferably an anion of a β-dicarbonylcompound or of an o-acylphenol. Examples of β-dicarbonyl compounds areacetylacetone, benzoylacetone, dibenzoylmethane, methyl acetoacetate,ethyl acetoacetate, butyl acetoacetate, lauryl acetoacetate, andα-acetylcyclohexanone. Examples of o-acylphenols are 2-acetylphenol,2-butyroylphenol, 2-acetylnaphthol, 2-benzoylphenol, andsalicylaldehyde. The enolate is preferably the anion of a β-dicarbonylcompound having from 5 to 20 carbon atoms.

The anions present in organic salts of zinc, calcium, magnesium,iron(II), manganese(II), or of cerium(III) are preferablyacetylacetonate or an aliphatic monocarboxylate having, for example,from 1 to 24 carbon atoms. Some of the particularly preferred salts aremagnesium acetate, magnesium laurate, magnesium stearate, zinc formate,zinc acetate, zinc oenanthate, zinc laurate, zinc stearate, calciumacetate, calcium laurate, calcium stearate, manganese acetate, manganeselaurate, manganese stearate, zinc acetylacetonate, calciumacetylacetonate, magnesium acetylacetonate, and manganeseacetylacetonate.

Mention may be made of the following preferred inorganic salts of zinc,calcium, magnesium, iron(II), manganese(II), and cerium(III): theiroxides, hydroxides, and carbonates, and also, in the case of magnesium,naturally occurring or synthetic dolomite or hydrotalcite. The inorganicsalts are used in the form of fine powders with average particle sizesof a few μm, preferably of a few nm.

The fine-particle polymer powders comprising at least one UV absorber,and the stabilizer mixtures of the invention, have excellent suitabilityfor stabilizing polymers with respect to exposure to UV radiation and,respectively, with respect to exposure to UV radiation, oxygen and heat.Examples of polymers which may be stabilized by the polymer powders and,respectively, stabilizer mixtures are:

-   1. Polymers of monoolefins and of diolefins, e.g. polypropylene,    polyisobutylene, poly-1-butene, poly-4-methyl-1-pentene,    polyisoprene, or polybutadiene; and polymers of cycloolefins, e.g.    polycyclopentene or polynorbonene; polyethylene (which may have been    crosslinked if appropriate), e.g. HDPE, HMWHDPE, UMHWHDPE, MDPE,    LDPE, LLDPE, BLDPE, VLDPE, and ULDPE.    -   The polyolefins, e.g. those based on the abovementioned        monoolefins, preferably polyethylene and polypropylene, may have        been prepared by any of the processes known from the literature,        in particular by the following processes:    -   (a) free-radical polymerization (generally carried out at high        pressures and temperatures);    -   (b) catalytic polymerization, using catalysts which usually        comprise one or more metals of groups IVB, VB, VIB, or VIII        (IUPAC groups 4, 5, 6, or 8/9/10) of the Periodic Table. These        metals generally have one or more ligands, e.g. oxides, halides,        alcoholates, esters, ethers, amines, alkyl radicals, alkenyl        radicals, and/or aryl radicals, and the coordination of the        ligands here may be π-coordination or σ-coordination. The metal        complexes themselves may be in free or supported form on        substrates; examples which may be mentioned of catalysts are        activated magnesium chloride, titanium(III) chloride, aluminum        oxide, or silicon oxide. Said catalysts may be either soluble or        else insoluble in the polymerization medium, and in the case of        the supported form here they are naturally insoluble. The        catalysts may be present alone or in the presence of other        activators, e.g. alkyl metal compounds, metal hydrides, halides,        or oxides of alkyl metal compounds or alkyl metal oxane        compounds (is this correct? what compounds are these?), the        metals of these activators being within groups IA, IIA, and/or        IIIA (IUPAC groups 1, 2 or 13) of the Periodic Table. Using a        simple method, these activators may be modified with other ester        groups, ether groups, amine groups, or silyl ether groups. These        catalytic systems are usually termed Phillips,        Standard-Oil-Indiana, Ziegler(Natta)-, TNZ-(DuPont),        metallocene, or single-site” catalysts (SSCs).-   2. Mixtures of polymers as described under item 1, e.g. mixtures of    polypropylene with polyisobutylene; mixtures of polypropylene with    polyethylene, such as PP/HDPE, PP/LDPE); mixtures of different types    of polyethylene, e.g. LDPE/HDPE.-   3. Copolymers of monoolefins and of diolefins with one another or    with other monomers containing vinyl groups. Examples of these    copolymers are ethylene-propylene copolymers, LLDPE and its mixtures    with LDPE, propylen-1-butene copolymers, propylene-isobutylene    copolymers, ethylene-1-butene copolymers, ethylene-hexene    copolymers, ethylene-methylpentene copolymers, ethylene-heptene    copolymers, ethylene-octene copolymers, propylene-butadiene    copolymers, isobutylene-isoprene copolymers, ethylene-alkyl acrylate    copolymers, ethylene-alkyl methacrylate copolymers, ethylene-vinyl    acetate copolymers, and copolymers of these with carbon monoxide.    Other examples are ethylene-acrylic acid copolymers and salts of    these (ionomers), and also terpolymers of ethylene with propylene    and a diene, e.g. hexadiene, dicyclopentadiene, or    ethylidenenorbornene; and mixtures of the copolymers mentioned with    one another or with the polymers listed under item (1), e.g.    polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl    acetate (EVA) copolymers, LDPE/ethylene-acrylic acid (EAA)    copolymers, LLDPE/EVA, LLDPE/EAA, and alternating or random    polyalkylene-carbon monoxide copolymers, and mixtures of these with    other polymers, e.g. with polyamides.-   4. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).-   5. Copolymers of styrene or α-methylstyrene with dienes or with    acrylic acid derivatives, e.g. styrene-butadiene,    styrene-acrylonitrile, styrene-alkyl methacrylate,    styrene-butadiene-alkyl acrylate, styrene-butadiene-alkyl    methacrylate, styrene-maleic anhydride,    styrene-acrylo-nitrile-methyl acrylate; high-impact-strength    mixtures involving styrene copolymers and involving other polymers,    e.g. involving polyacrylates, involving diene polymers, or involving    ethylene-propylene-diene terpolymers, or involving block copolymers    of styrene, e.g. styrene-butadiene-styrene,    styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, or    styrene-ethylene-propylene-styrene.-   6. Graft copolymers of styrene or α-methylstyrene, e.g. styrene in    polybutadiene, styrene in polybutadiene-styrene copolymers or in    polybutadiene-acrylonitrile copolymers; styrene and acrylonitrile    (or methacrylonitrile) in polybutadiene; styrene, acrylonitrile, and    methyl methacrylate in polybutadien; styrene and maleic anhydride in    polybutadiene; styrene, acrylonitrile, and maleic anhydride or    maleimide in polybutadiene; styrene and maleimide in polybutadiene;    styrene and alkyl acrylates or alkyl methacrylates in polybutadiene;    styrene and acrylonitrile in ethylene-propylene-diene terpolymers,    styrene and acrylonitrile in polyalkyl acrylates or in polyalkyl    methacrylates, styrene and acrylonitrile in acrylate-butadiene    copolymers, and also mixtures of copolymers listed under item (5),    e.g. mixtures of known copolymers, for example ABS, MBS, ASA, or    AES.-   7. Halogen-containing polymers, e.g. polychloroprene, chlorinated    elastomers, chlorinated or brominated isobutylene-isoprene    copolymers (halobutyl rubber), chlorinated or chlorosulfonated    polyethylene, chlorinated ethylene copolymers, homopolymers and    copolymers of epichlorohydirn, and in particular polymers of    halogen-containing vinyl compounds, for example polyvinyl chloride,    polyvinylidene chloride, polyvinyl fluoride, or polyvinylidene    fluoride; and also their copolymers, for example those based on    vinyl chloride-vinylidene chloride, vinyl chloride-vinyl acetate or    vinylidene chloride-vinyl acetate.-   8. Polymers derived from α,β-unsaturated acids and from their    derivatives, e.g. polyacrylates and polymethacrylates, polymethyl    methacrylates, polyacrylamides, and polyacrylonitriles,    impact-modified with butyl acrylate.-   9. Copolymers based on monomers of item (8) with one another or with    other unsaturated monomers, e.g acrylonitrile-butadiene copolymers,    acrylonitril-alkyl acrylate copolymers, acrylonitrile-alkoxyalkyl    acrylate copolymers, or acrylonitrile-vinyl halide copolymers or    acrylonitrile-alkyl methacrylate-butadiene terpolymers.-   10. Polymers derived from unsaturated alcohols and amines or from    their acyl or acetal derivatives, e.g. polyvinyl alcohol, polyvinyl    acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate,    polyvinyl butyral, polyallyl phthalate, or polyallylmelamine; and    their copolymers with olefins listed under item (1).-   11. Homopolymers and copolymers of open-chain or cyclic ethers, e.g.    polyalkylene glycols, polyethylene oxide, polypropylene oxide, or    copolymers of the abovementioned compounds with bisglycidyl ethers.-   12. Polyacetals, e.g. polyoxymethylene and polyoxymethylene    containing comonomers, such as ethylene oxide; polyacetals modified    using thermoplastic polyurethanes, using acrylates, or using MBS.-   13. Polyphenylene oxides and polyphenylene sulfides and mixtures of    either of these with styrene polymers or with polyamides.-   14. Polyurethanes derived firstly from hydroxy-terminated    polyethers, polyesters, or polybutadienes, and secondly from    aliphatic or aromatic polyisocyanates, or derived from the    precursors of each of these.-   15. Polyamides and copolyamides derived from diamines and from    dicarboxylic acids, and/or aminocarboxylic acids, or from    corresponding lactams, e.g. nylon-4, nylon-6, nylon-6,6, 6,10, 6,9,    6,12, 4,6, 12,12, or nylon-11 or nylon-12, aromatic polyamides based    on m-xylenediamine and adipic acid; polyamides based on    hexamethylenediamine and isophthalic and/or terephthalic acid, with    or without an elastomer as modifier, e.g.    poly-2,4,4-trimethylhexamethyleneterephthalamide or    poly-m-phenyleneisophthalamide; and also block copolymers of the    above polyamides with polyolefins, with olefinic copolymers, with    ionomers, or with elastomers, chemically bonded or grafted, or with    polyethers, e.g. polyethylene glycol, polypropylene glycol or    polytetramethylene glycol; and also polyamides or copolyamides    modified using EPDM or ABS and polyamides condensed during    processing (“RIM polyamide systems”).-   16. Polyureas, polyimides, polyamideimides, polyetherimides,    polyesterimides, polyhydantoins, and polybenzoimidazoles.-   17. Polyesters derived from dicarboxylic acids and from diols,    and/or from hydroxycarboxylic acids or from the corresponding    lactones, e.g. polyethylene terephthalate, polybutylene    terephthalate, poly-1,4-dimethylolcyclohexane terephthalate, and    polyhydroxybenzoates, and also block copolyetheresters derived from    polyethers using hydroxy-terminated groups, and also polyesters    modified using polycarbonates or using MBS.-   18. Polycarbonates and polyester carbonates.-   19. Polysulfones, polyether sulfones, and polyether ketones.-   20. Crosslinked polymers derived firstly from aldehydes and secondly    from phenols, from urea, or from melamines, e.g. phenol-formaldehyde    resins, urea-formaldehyde resins, and melamine-formaldehyde resins.-   21. Drying and non-drying alkyd resins.-   22. Resins based on unsaturated polyesters, where these derive from    copolyesters of saturated and unsaturated carboxylic acids with    polyhydric alcohols and vinyl compounds as crosslinking agents, and    also the abovementioned halogen-containing flame-retardant resins.-   23. Crosslinkable acrylic resins derived from substituted acrylates,    e.g. epoxy-derived acrylates, urethane-derivated acrylates, or    polyester-derived acrylates.-   24. Alkyd resins, resins based on polyesters, or acrylated,    melamine-crosslinked resins, resins based on urea, resins based on    isocyanates, resins based on isocyanurates, resins based on    polyisocyanates, or epoxy resins.-   25. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic,    heterocyclic, or aromatic glycidyl compounds, e.g. products from    diglycidyl ethers of bisphenol A and bisphenol F, crosslinked using    conventional crosslinking agents, e.g. using anhydrides or amines,    in the presence or absence of accelerators.-   26. Naturally occurring polymers, such as cellulose, rubber,    gelatin, and their derivatives chemically modified to obtain    homologous polymers, e.g. cellulose acetates, cellulose propionates,    cellulose butyrates, or cellulose ethers, e.g. methylcellulose; and    also hydrocarbon resins (rosins) and their derivatives.-   27. Mixtures of the polymers mentioned (polyblends) e.g. PP/EPDM,    polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS,    PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PU,    PC/thermoplastic PU, POM/acrylates, POM/MBS, PPO/HIPS, PPO/PA 6.6,    and copolymers, PA/HDPE, PAPP, PAPPO, PBT/PC/ABS, PBT/PET/PC.-   28. Naturally occurring or synthetic organic materials which are    pure monomeric compounds, and also mixtures of these, e.g. mineral    oils, animal or vegetable oils, fats or waxes, oils, fats, or waxes    based on synthetic esters, e.g. phthalates, adipates, phosphates,    and trimellitates, and also mixtures of synthetic esters with    mineral oils in any desired ratio by weight, and also aqueous    emulsions of the organic materials mentioned.-   29. Aqueous emulsions of naturally occurring or synthetic rubber,    e.g. natural latex or latices based on carboxylated    styrene-butadiene copolymers.

The fine-particle polymer powders comprising at least one UV absorber,or the stabilizer mixtures of the invention, may also be used in thepreparation of polyurethanes, in particular in the preparation ofpolyurethane foams. The result is that the resultant polyurethanes andpolyurethane foams are stabilized with respect to exposure to UVradiation or, respectively, with respect to exposure to UV radiation,oxygen and heat.

One way of obtaining the polyurethanes is by reaction of polyethers,polyesters, and polybutadienes which contain terminal hydroxy groupswith aliphatic or aromatic polyisocyanates.

Polyethers having terminal hydroxy groups are well-known and may beprepared, for example, by polymerizing epoxides, e.g. ethylene oxide,propylene oxide, butylene oxide, styrene oxide, or epichlorohydrin, forexample in the presence of boron trifluoride, or via an additionreaction of the epoxides, alone or in mixture with one another, or in asuccessive reaction using starters which contain reactive hydrogenatoms, e.g. water, alcohols, ammonia, or amines, for example ethyleneglycol, propylene 1,2- or 1,3-glycol, trimethylolpropane,4,4′-dihydroxydiphenylpropane, aniline, ethanolamine, orethylenediamine. It is also possible to use polyethers which containsucrose. In most cases preference is given to polyethers having a largenumber of primary OH groups (up to 90% of all of the OH groups presentin the polyether). Use may also be made of polyethers modified usingvinyl polymers, one method of preparing these polyethers beingpolymerization of styrene and acrylonitrile in the presence ofpolyethers which are polybutadienes having OH groups.

The abovementioned compounds are polyhydroxy compounds and have molarmasses in the range from 400 to 10,000 g/mol, in particular from 800 to10,000 g/mol, preferably from 1,000 to 6,000 g/mol, the polyethers thushaving, for example, at least two, usually from 2 to 8, but preferablyfrom 2 to 4, hydroxy groups, and being thus known for the preparation ofhomogeneous polyurethanes and of cellular polyurethanes.

It is, of course, also possible to use mixtures of the abovementionedcompounds which have at least two hydrogen atoms reactive towardisocyanate groups and preferably have a molar mass of from 400 to 10,000g/mol.

Suitable compounds are aliphatic, cycloaliphatic, araliphatic, aromatic,or heterocyclic polyisocyanates, e.g. ethylene diisocyanate,tetramethylene-1,4-diisocyanate, hexamethylene 1,6-diisocyanate,dodecane 1,12-diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane1,3- or -1,4-diisocyanate, and also mixtures of these isomers;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane,hexahydrotolylene 2,4- and 2,6-diisocyanate and also mixtures of theseisomers; hexahydrophenylene 1,3- and/or 1,4-diisocyanate,perhydrodiphenylmethane 2,4′- and/or 4,4′-diisocyanate, phenylene 1,3-and 1,4-diisocyanate, tolylene 2,4- and 2,6-diisocyanate, and alsomixtures of these isomers; diphenylmethane 2,4′- and/or-4,4′-diisocyanate, naphthylene 1,5-diisocyanate, triphenylmethane4,4′,4″-triisocyanate, polyphenyl polymethylene polyisocyanates,obtained by aniline/formaldehyde condensation followed by phosgenation,m- and p-isocyanatophenylsulfonyl isocyanates, perchlorinatedarylpolyisocyanates, polyisocyanates containing carbodiimide groups,polyisocyanates containing allophanate groups, polyisocyanatescontaining isocyanurate groups, polyisocyanates containing urethanegroups, polyisocyanates containing acylated urea groups, polyisocyanatescontaining biuret groups, polyisocyanates containing ester groups, thereaction products of the abovementioned isocyanates with acetals, andalso polyisocyanates which contain residues of polymeric fatty acids.

It is also possible to use distillation residues which containisocyanate groups, these residues arising during industrial productionof isocyanates and being in undiluted form or dissolved in one or moreof the abovementioned polyisocyanates. It is also possible to use anydesired mixture of the abovementioned polyisocyanates.

It is preferable to use polyisocyanates which are easily obtainableindustrially, examples of these being tolylene 2,4- and2,6-diisocyanate, and also any desired mixture of these isomers (“TDI”);polyphenyl polymethylene polyisocyanates obtained byaniline/formaldehyde condensation followed by phosgenation (“crudeMDI”); polyisocyanates containing carbodiimide groups, containingurethane groups, containing allophanate groups, containing isocyanurategroups, containing urea groups, and/or containing biuret groups (knownas modified polyurethanes).

For the purposes of the present invention, paints, and the binderspresent in them, are among the polymers which can be stabilized by thepolymer powders comprising UV absorbers, or by the stabilizer mixturesof the invention. These binders are usually composed of, or comprise,one or more of the polymers described under the abovementioned points 1to 29, in particular of one or more polymers described under points 20to 25.

The polymers which may be stabilized by the polymer powders comprisingUV absorbers or by the stabilizer mixtures of the invention arepreferably those naturally occurring, semi-synthetic or syntheticpolymers selected from the groups described above. The polymer powderscomprising UV absorbers, or the stabilizer mixtures of the invention,are particularly used in the stabilization of thermoplastic polymers,preferably of polyolefins, particularly preferably of polyethylene andpolypropylene, or their copolymers with mono- or diolefins.

Irrespective of whether the preferred embodiment is used, the presentinvention therefore also provides polymers, in particular polyolefins,stabilized with respect to exposure to UV radiation and comprising atleast one UV absorber.

Irrespective of whether the preferred embodiment is used, the presentinvention also provides polymers, in particular polyolefins, stabilizedwith respect to exposure to UV radiation, oxygen and heat and comprisingan effective amount of stabilizer mixtures of the invention.

The present invention also provides articles produced from theabovementioned inventive polymers, in particular polyolefins, stabilizedwith respect to exposure to UV radiation and, respectively, stabilizedwith respect to exposure to UV radiation, oxygen and heat.

Component (a) and the at least one other component selected from thegroup consisting of components (b) to (f) of the stabilizer mixtures ofthe invention may be either separate or else have been mixed with oneanother when added to the polymers.

The amount of component (a) added to the polymers to be stabilized isfrom 0.0005 to 5% by weight, preferably from 0.001 to 2% by weight, andin particular from 0.01 to 2% by weight, based on the weight of thepolymers to be stabilized.

The amount of each of the components (b) and/or (c) and/or (d), and/or(e), and/or (f) added to the polymers to be stabilized is from 0.01 to10% by weight, preferably from 0.01 to 5% by weight, particularlypreferably from 0.025 to 3% by weight, and in particular from 0.025 to1% by weight, based on the weight of the materials to be stabilized.

If components (a) and (b), and also, where appropriate, (c) and/or (d),and/or (e), and/or (f) of the stabilizer mixtures of the invention areadded in the form of a mixture to the materials to be stabilized, theiramounts present in the stabilizer mixtures of the invention are theamounts described above (based on the weight of the materials to bestabilized).

Preferred stabilizer mixtures comprise, besides components (a) and (b),at least one compound selected from the group consisting of stericallyhindered phenols as component (c) and also, where appropriate, othercompounds selected from the group of components (d), (e), and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered amines as component (d) and also, where appropriate,other compounds selected from the group of components (c), (e), and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group of the chromanes ascomponent (e), and also, where appropriate, other compounds selectedfrom the group of components (c), (d), and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one organic or inorganic salt selected from the groupconsisting of zinc salts, calcium salts, magnesium salts, cerium salts,iron salts, and manganese salts, as component (f), and also, whereappropriate, other compounds selected from the group of components (c),(d), and (e).

Preferred stabilizer mixtures comprise, besides components (a) and (b),at least one compound selected from the group consisting of stericallyhindered phenols as component (c), and at least one compound selectedfrom the group consisting of sterically hindered amines as component(d), and also, where appropriate, other compounds selected from thegroup of components (e) and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered phenols as component (c), and at least one compoundselected from the group of the chromanes as component (e) and also,where appropriate, other compounds selected from the group of components(d) and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered phenols as component (c), and at least one organicor inorganic salt selected from the group consisting of zinc salts,calcium salts, magnesium salts, cerium salts, iron salts, and manganesesalts, as component (f), and also, where appropriate other compoundsselected from the group of components (d) and (e).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered amines as component (d), and at least one compoundselected from the group of the chromanes as component (e), and also,where appropriate, other compounds selected from the group of components(c) and (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered amines as component (d), and at least one organic orinorganic salt selected from the group consisting of zinc salts, calciumsalts, magnesium salts, cerium salts, iron salts, and manganese salts ascomponent (f), and also, where appropriate, other compounds selectedfrom the group of components (c) and (e).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group of the chromanes ascomponent (e), and at least one organic or inorganic salt selected fromthe group consisting of zinc salts, calcium salts, magnesium salts,cerium salts, iron salts, and manganese salts, as component (f), andalso, where appropriate, other compounds selected from the group ofcomponents (c) and (d).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered phenols as component (c), at least one compoundselected from the group consisting of sterically hindered amines ascomponent (d), and at least one compound selected from the group of thechromanes as component (e), and also, where appropriate, other compoundsof component (f).

Other preferred stabilizer mixtures comprise, besides components (a) and(b), at least one compound selected from the group consisting ofsterically hindered phenols as component (c), at least one compoundselected from the group consisting of sterically hindered amines ascomponent (d), and at least one organic or inorganic salt selected fromthe group consisting of zinc salts, calcium salts, magnesium salts,cerium salts, iron salts, and manganese salts as component (f), andalso, where appropriate other compounds of component (e).

It is, of course, also possible for the polymers to receive additions ofundiluted UV absorbers, i.e. UV absorbers not embedded within a polymermatrix or partially or completely encapsulated by a polymer matrix,alongside the polymer powders comprising UV absorbers, and/or for thestabilizer mixtures of the invention to additionally comprise straightUV absorbers, for example those listed at the outset.

The stabilizer mixtures of the invention may moreover comprise otherstabilizers (costabilizers), selected from the groups listed below.

1. Antioxidants and Free-Radical Scavengers

1.1 Alkylated Monophenols, for Example:

-   2,6-di-tert-butyl-4-methylphenol;-   2-tert-butyl-4,6-dimethylphenol;-   2,6-di-tert-butyl-4-ethylphenol;-   2,6-di-tert-butyl-4-n-butylphenol;-   2,6-di-tert-butyl-4-isobutylphenol;-   2,6-dicyclopentyl-4-methylphenol;    2-(α-methylcyclohexyl)-4,6-dimethylphenol;    2,6-dioctadecyl-4-methylphenol;-   2,4,6-tricyclohexylphenol;-   2,6-di-tert-butyl-4-methoxymethylphenol; nonyl phenols having linear    or branched alkyl chains, such as 2,6-dinonyl-4-methylphenol;    2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol;-   2,4-dimethyl-6-(1′-methylheptadec-1′-yl)phenol;-   2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol; and their mixtures.

1.2 Alkylthiomethylphenols, for Example:

-   2,4-dioctylthiomethyl-6-tert-butylphenol;-   2,4-dioctylthiomethyl-6-methylphenol;-   2,4-dioctylthiomethyl-6-ethylphenol;-   2,6-didodecylthiomethyl-4-nonylphenol.

1.3 Hydroquinones and Alkylated Hydroquinones, for Example:

-   2,6-di-tert-butyl-4-methoxyphenol;-   2,5-di-tert-butylhydroquinone; 2,5-di-tert-amylhydroquinone;-   2,6-diphenyl-4-octadecyloxyphenol;-   2,6-di-tert-butylhydroquinone;-   2,5-di-tert-butyl-4-hydroxyanisole;-   3,5-di-tert-butyl-4-hydroxyanisole;-   3,5-di-tert-butyl-4-hydroxyphenyl stearate;-   bis(3,5-di-tert-butyl-4-hydroxyphenyl)adipate.

1.4 Tocopherols, for example: α-tocopherol, β-tocopherol, γ-tocopherol,δ-tocopherol and their mixtures (vitamin E).

1.5 Hydroxylated Thiodiphenyl Ethers, for Example:

-   2,2′-thiobis(6-tert-butyl-4-methylphenol);-   2,2′-thiobis(4-octylphenol);-   4,4′-thiobis(6-tert-butyl-3-methylphenol);-   4,4′-thiobis(6-tert-butyl-2-methylphenol);-   4,4′-thiobis(3,6-di-sec-amylphenol);-   4,4′-bis(2,6-dimethyl-4-hydroxyphenyl)disulfide.

1.6 Alkylidenebisphenols, for Example:

-   2,2′-methylenebis(6-tert-butyl-4-methylphenol);-   2,2′-methylenebis(6-tert-butyl-4-ethylphenol);-   2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol];-   2,2′-methylenebis(4-methyl-6-cyclohexylphenol);-   2,2′-methylenebis(6-nonyl-4-methylphenol);-   2,2′-methylenebis(4,6-di-tert-butylphenol);-   2,2′-ethylidenebis(4,6-di-tert-butylphenol);-   2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol);-   2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol];-   2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol];-   4,4′-methylenebis(2,6-di-tert-butylphenol);-   4,4′-methylenebis(6-tert-butyl-2-methylphenol);-   1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane;-   2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol;    1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane;-   1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane;    ethylene glycol-   bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate];-   bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene;-   bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate;-   1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane;-   2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane;-   2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane;-   1,1,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7 Benzyl Compounds Containing Oxygen, Nitrogen, or Sulfur, forExample:

-   3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether;-   octadecyl 4-hydroxy-3,5-dimethylbenzylmercaptoacetate;-   tridecyl 4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate;-   tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine;-   bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate;    bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide; isooctyl-   3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.8 Hydroxybenzylated malonates, for example: dioctadecyl2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate;

-   dioctadecyl 2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate;    didodecyl    mercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate;    bis[4-(1,1,3,3-tetramethylbutyl)phenyl]2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9 Aromatic Hydroxybenzyl Compounds, for Example:

-   1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene;-   1,4-bis(3,5-di-tert-butylhydroxybenzyl)-2,3,5,6-tetramethylbenzene;    2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.10 Triazine Compounds, for Example:

-   2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine;-   2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine;-   2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine;-   2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine;    1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate;-   1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate;-   2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine;-   1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine;-   1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.

1.11 Benzylphosphonates, for example: dimethyl2,5-di-tert-butyl-4-hydroxybenzylphosphonate; diethyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate; dioctadecyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate; dioctadecyl5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate; the calcium salts ofthe monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12 Acylaminophenols, for example: 4-hydroxylauranilide;4-hydroxystearanilide; octylN-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13 Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, for example:

-   -   methanol; ethanol; n-octanol; isooctanol; octadecanol;        1,6-hexanediol; 1,9-nonanediol; ethylene glycol;        1,2-propanediol; neopentyl glycol; thiodiethylene glycol;        diethylene glycol; triethylene glycol; pentaerythritol;        tris(hydroxyethyl)isocyanurate; N,N′-bis(hydroxyethyl)oxalamide;        3-thiaundecanol; 3-thiapentadecanol; trimethylhexanediol;        trimethylolpropane;        4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14 Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acidwith mono- or polyhydric alcohols, for example: methanol; ethanol;n-octanol; isooctanol; octadecanol; 1,6-hexanediol; 1,9-nonanediol;ethylene glycol; 1,2-propanediol; neopentyl glycol; thiodiethyleneglycol; diethylene glycol; triethylene glycol; pentaerythritol;tris(hydroxyethyl)isocyanurate; N,N′-bis(hydroxyethyl)oxalamide;3-thiaundecanol; 3-thiapentadecanol; trimethylhexanediol;trimethylolpropane;4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, for example: methanol; ethanol; n-octanol;isooctanol; octadecanol; 1,6-hexanediol; 1,9-nonanediol; ethyleneglycol; 1,2-propanediol; neopentyl glycol; thiodiethylene glycol;diethylene glycol; triethylene glycol; pentaerythritol;tris(hydroxyethyl)isocyanurate; N,N′-bis(hydroxyethyl)oxalamide;3-thiaundecanol; 3-thiapentadecanol; trimethylhexanediol;trimethylolpropane;4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16 Esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid with mono-or polyhydric alcohols, for example: methanol; ethanol; n-octanol;isooctanol; octadecanol; 1,6-hexanediol; 1,9-nonanediol; ethyleneglycol; 1,2-propanediol; neopentyl glycol; thiodiethylene glycol;diethylene glycol; triethylene glycol; pentaerythritol;tris(hydroxyethyl)isocyanurate; N,N′-bis(hydroxyethyl)oxalamide;3-thiaundecanol, 3-thiapentadecanol; trimethylhexanediol;trimethylolpropane;4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17 Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, forexample:

-   N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine;-   N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine;-   N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine;-   N,N′-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl-oxy)ethyl]oxalamide    (Naugard® XL-1 from Uniroyal).

1.18 Ascorbic Acid and Derivatives, Such as Vitamin C and PalmitolAscorbate.

1.19 Amine Antioxidants, for Example:

-   -   N,N′-diisopropyl-p-phenylenediamine;        N,N′-di-sec-butyl-p-phenylenediamine;        N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine;        N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine;        N,N′-bis(1-methylheptyl)-p-phenylenediamine;        N,N′-dicyclohexyl-p-phenylenediamine;        N,N′-diphenyl-p-phenylenediamine;        N,N′-bis(2-naphthyl)-p-phenylenediamine;        N-isopropyl-N′-phenyl-p-phenylenediamine;        N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine;        N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine;        N-cyclohexyl-N′-phenyl-p-phenylenediamine;        4-(p-toluenesulfonamoyl)diphenylamine;        N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine;        diphenylamine; N-allyldiphenylamine; 4-isopropoxydiphenylamine;        N-phenyl-1-naphthylamine;        N-(4-tert-octylphenyl)-1-naphthylamine;        N-phenyl-2-naphthylamine; dioctylphenylamines; for example        p,p′-(di-tert-octylphenyl)amine; 4-n-butylaminophenol;        4-butyrylaminophenol; 4-nonanoylaminophenol;        4-dodecanoylaminophenol; 4-octadecanoylaminophenol;        bis(4-methoxyphenyl)amine;        2,6-di-tert-butyl-4-dimethylaminomethylphenol;        2,4′-diaminodiphenylmethane; 4,4′-diaminodiphenylmethane;        N,N,N′,N′-tetramethyl-4,4′-diaminodiphenylmethane;        1,2-bis[(2-methylphenyl)amino]ethane;        1,2-bis(phenylamino)propane;        bis[4-(1′,3′-dimethylbutyl)phenyl]amine, mixtures of mono- and        dialkylated tert-butyl/tert-octyldiphenylamines; mixtures of        mono- and dialkylated nonyldiphenylamines; mixtures of mono- and        dialkylated dodecyldiphenylamines; mixtures of mono- and        dialkylated isopropyl/isohexyl-diphenylamines; mixtures of mono-        and dialkylated tert-butyldiphenylamine;        2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine;        mixtures of mono- and dialkylated        tert-butyl/tert-octylphenothiazines; mixtures of mono- and        dialkylated tert-octylphenothiazines; N-allylphenothiazine;        N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene;        N,N-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine;        bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate;        2,2,6,6-tetramethylpiperidin-4-one;        2,2,6,6-tetramethylpiperidin-4-ol.

1.20 Benzofuranones and indolinones, for example: the compoundsdisclosed in the specifications U.S. Pat. No. 4,325,863, U.S. Pat. No.4,338,244, U.S. Pat. No. 5,175,312, U.S. Pat. No. 5,216,052, U.S. Pat.No. 5,252,643, DE 43 16 611 A1, DE 43 16 622 A1, DE 43 16 876 A1, EP 589839 A1 and EP 591 102 A1,

-   3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one;-   3-[4-(2-(stearoyloxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one;-   3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one;-   5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one;-   3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuranon-2-one;-   3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one;    in particular the compound of the formula

1.21 Compounds of the Formulae:

-   -   and their tautomers of the formulae

-   -   where    -   R² is L′ or a —(R₂N)C═C(L′)₂ group, where the two radicals R and        L′, respectively, may be identical or different from one        another; L′ is —CN, —COR, —COOR, —SO₂R; L is oxygen, ═NR or        sulfur; and R¹, R³, and R, independently of one another, are        hydrogen; linear or branched C₁-C₂₄-alkyl; linear or branched        C₂-C₂₄-alkenyl; linear or branched C₂-C₂₄-alkynyl; linear or        branched C₂-C₈-alkoxyalkyl; unsubstituted or substituted        C₃-C₁₂-cycloalkyl; an unsubstituted or substituted five- or        six-membered heterocyclic radical which contains at least one        heteroatom selected from the group consisting of oxygen,        nitrogen and sulfur; unsubstituted or substituted C₆-C₂₀-aryl.    -   The preparation of these compounds is described by way of        example in the specification WO 95/04733, and their use as a        component of stabilizer mixtures for polymers is known from the        earlier German Patent Application 102 50 260.9.

2. Other UV Absorbers and Light Stabilizers

2.1 Nickel compounds, for example: nickel complexes of2,2′-thiobis[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or 1:2complex, with or without additional ligands such as n-butylamine;triethanolamine or N-cyclohexyldiethanolamine; nickeldibutyldithiocarbamate; nickel salts of monoalkyl esters; for example ofmethyl or ethyl ester; of 4-hydroxy-3,5-di-tert-butylbenzylphosphonicacid; nickel complexes with ketoximes; e.g. with2-hydroxy-4-methylphenyl undecyl ketoxime; nickel complexes of1-phenyl-4-lauroyl-5-hydroxypyrazole; with or without additionalligands.

2.2 Other sterically hindered amines and their N-alkoxy derivatives, forexample: the condensation product of1-(2-hydroxyethyl)-2,2,6,6-tetra-4-hydroxypiperidine and succinic acid,the linear or cyclic condensation product ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidinyl)hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,tris(2,2,6,6-tetramethyl-4-piperidinyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)1,2,3,4-butanetetracarboxylate,1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone, the linear orcyclic condensation product ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidinyl)hexamethylenediamine and4-morpholine-2,6-dichloro-1,3,5-triazine, the condensation product of2-chloro-4,6-di(4-n-butylamino-2,2,6,6-tetramethylpiperidinyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane, the condensation product of2-chloro-4,6-di(4-n-butylamino-1,2,2,6,6-pentamethylpiperidinyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane,3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidinyl)pyrrolidin-2,5-dione, amixture of 4-hexadecyloxy- and4-stearyloxy-2,2,6,6-tetramethylpiperidine, the condensation product ofN—N′-bis(2,2,6,6-tetramethyl-4-piperidinyl)hexamethylenediamine and4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, the condensation productof 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine,4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6],N-(2,2,6,6-tetramethyl-4-piperidinyl)-n-dodecylsuccinimide,N-(1,2,2,6,6-pentamethyl-4-piperidinyl)-n-dodecylsuccinimide, thereaction product of7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro[4.5]decaneand epichlorohydrin,1,1-bis(1,2,2,6,6-pentamethyl-4-piperidinyloxycarbonyl)-2-(4-methoxyphenyl)ethene,the diester of 2-methoxymethylenemalonic acid with1,2,2,6,6-pentamethyl-4-hydroxypiperidine.

2.3 Oxamides, for example: 4,4′-dioctyloxyoxanilide;2,2′-diethoxyoxanilide; 2,2′-dioctyloxy-5,5′-di-tert-butoxanilide;2,2′-didodecyloxy-5,5′-di-tert-butyloxanilide;2-ethoxy-2′-ethyloxanilide; N,N′-bis(3-dimethylaminopropyl)oxamide;2-ethoxy-5-tert-butyl-2′-ethoxanilide and its mixtures with2-ethoxy-2′-ethyl-5,4′-di-tert-butoxanilide; and mixtures ofdisubstituted ortho- and para-methoxyoxanilides, and mixtures ofdisubstituted ortho- and para-ethoxyoxanilides.

3. “Metal deactivators”, for example: N,N′-diphenyloxamide;N-salicylal-N′-salicyloylhydrazine; N,N′-bis(salicyloyl)-hydrazine;N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine;3-salicyloylamino-1,2,4-triazole; bis(benzylidene)oxalyl dihydrazide;oxanilide; isophthaloyl dihydrazide; sebacoyl bisphenylhydrazide;N,N′-diacetyladipoyl dihydrazide; N,N′-bis(salicyloyl)oxalyldihydrazide; N,N′-bis(salicyloyl)thiopropionyl dihydrazide.

4. Hydroxylamines, for example: N,N-dibenzylhydroxylamine;N,N-diethylhydroxylamine; N,N-dioctylhydroxylamine;N,N-dilaurylhydroxylamine; N,N-ditetradecylhydroxylamine;N,N-dihexadecylhydroxylamine; N,N-dioctadecylhydroxylamine;N-hexadecyl-N-octadecylhydroxylamine;N-heptadecyl-N-octadecylhydroxylamine; N,N-dialkylhydroxylamines derivedfrom hydrogenated tall amines.

5. Nitrones, for example: N-benzyl-α-phenylnitrone;N-ethyl-α-methylnitrone; N-octyl-α-heptylnitrone;N-lauryl-α-undecylnitrone; N-tetradecyl-α-tridecylnitrone;N-hexadecyl-α-pentadecylnitrone; N-octadecyl-α-heptadecylnitrone;N-hexadecyl-α-heptadecylnitrone; N-octadecyl-α-pentadecylnitrone;N-heptadecyl-α-heptadecylnitrone; N-octadecyl-α-hexadecylnitrone; anitrone derived from hydrogenated tall amines.

6. Thiosynergists, for example: dilauryl thiodipropionate; distearylthiodipropionate.

7. Agents capable of destroying peroxides, for example: esters ofβ-thiodipropionic acid, for example the lauryl; stearyl; myristyl ortridecyl ester; mecaptobenzimidazole; or the zinc salt of2-mercaptobenzimidazole; zinc dibutyldithiocarbamate; dioctadecyldisulfide; pentaerythritol tetrakis(β-dodecylmercapto)propionate.

8. Polyamide stabilizers, for example: copper salts in combination withcompounds of iodine and/or of phosphorus, other examples being salts ofdivalent manganese.

9. Basic costabilizers, for example: melamine, polyvinylpyrrolidone,dicyandiamide, triallyl cyanurate, urea derivatives, hydrazinederivatives, amines, polyamides, polyurethanes, the alkali metal andalkaline earth metal salts of high-molecular-weight fatty acids, forexample calcium stearate, zinc stearate, magnesium stearate, magnesiumbehenate, sodium ricinoleate, potassium palmitate, antimonypyrocatecholate, tin pyrocatecholate, zinc pyrocatecholate.

10. Nucleating agents, for example: inorganic substances, examples beingtalc, metal oxides, (such as titanium dioxide or magnesium oxide),phosphates, carbonates or sulfates (preferably of the alkaline earthmetals); organic compounds, such as mono- or polycarboxylic acids andalso their salts, (for example 4-tert-butylbenzoic acid, adipic acid;diphenylacetic acid; sodium succinate or sodium benzoate); polymericcompounds, such as ionic copolymers (“ionomers”).

11. Fillers and reinforcing agents, for example: calcium carbonate,silicates, glass fibers, glass beads, talc, kaolin, mica, bariumsulfate, metal oxides and metal hydroxides, carbon black, graphite, woodflour and other powders or fibers of other natural products, syntheticfibers.

12. Other additives, for example: plasticizers, dyes, pigments,lubricants, emulsifiers, rheological additives, catalysts, levelingassistants, optical brighteners, flame retardants, antistatic agents,blowing agents.

Where appropriate, from 0.01 to 10% by weight of the abovementionedstabilizers (costabilizers), based on the weight of the polymers to bestabilized, may be added to the polymers to be stabilized.

Where appropriate, from 0.01 to 40% by weight of the fillers andreinforcing agents described under item 11, such as talc, calciumcarbonate, mica, or kaolin, based on the weight of the polymers to bestabilized, may be added to the polymers to be stabilized.

Where appropriate, from 0.01 to 60% by weight of the fillers andreinforcing agents described under item 11, such as metal hydroxides, inparticular aluminum hydroxide or magnesium hydroxide, based on theweight of the polymers to be stabilized, may be added to the polymers tobe stabilized.

Where appropriate, from 0.01 to 5% by weight of carbon black filler,based on the weight of the polymers to be stabilized, may be added tothe polymers to be stabilized.

Where appropriate, from 0.01 to 20% by weight of the reinforcing agentglass fibers, based on the weight of the polymers to be stabilized, maybe added to the polymers to be stabilized.

Irrespective of whether the preferred embodiments are used, the presentinvention also provides a process for stabilizing polymers, inparticular polyolefins, with respect to exposure to UV radiation, oxygenand heat, which comprises adding, to the polymers, an effective amountof stabilizer mixtures of the invention.

Components (a) and (b), and/or (c), and/or (d), and/or (e), and/or (f)are incorporated—individually or in a mixture with one another and,where appropriate, with other stabilizers (costabilizers)—into thepolymers to be stabilized by methods known per se, e.g. prior to orduring processing, or the stabilizer mixtures of the invention aredissolved or suspended in a solvent or suspension medium and added tothe polymers to be stabilized prior to or after evaporation of thesolvent or suspension medium. Masterbatches may also be prepared fromthe stabilizer mixtures of the invention, their content of thesemixtures being from 2.5 to 25% by weight, based on the total eight ofthe masterbatch.

The stabilizer mixtures of the invention, where appropriate in thepresence of other stabilizers (costabilizers), may be added, forexample, after the polymerization process to the polymers to bestabilized, or else during the polymerization process, or prior to thecrosslinking process.

The stabilizer mixtures of the invention, where appropriate in thepresence of other stabilizers (costabilizers), may be in pure form, orelse included within waxes, within oils, or within polymers, when addedto the polymers to be stabilized.

Stabilizer mixtures of the invention, where appropriate in the presenceof other stabilizers (costabilizers) capable of use in dissolved ormolten form may also be sprayed into the polymers to be stabilized. Thisspray-addition process may advantageously be undertaken with the aid ofthe gas used to deactivate the polymerization catalyst, and togetherwith the gas.

In the case of spherically polymerized polyolefins, it can beadvantageous to spray the stabilizer mixtures of the invention jointly,where appropriate in the presence of other stabilizers (costabilizers).

The polymers stabilized according to the invention may be shaped invarious ways, for example as films, fibers, tapes, melt compositions,profiles, or injection moldings.

1. A stabilizer mixture, comprising (a) at least one polymer powderwhich comprises at least one UV absorber, and (b) at least one compoundselected from the group consisting of organic phosphites, organicphosphines, and organic phosphonites, and at least one other componentselected form the group consisting of: (c) at least one compoundselected from the group consisting sterically hindered phenols, (d) atleast one compound selected from the group consisting stericallyhindered amines, (e) at least one compound selected from the group ofthe chromanes, and (f) at least one organic or inorganic salt selectedfrom the group consisting of zinc salts, calcium salts, magnesium salts,cerium salts, iron salts and manganese salts.
 2. The stabilizer mixtureas claimed in claim 1, wherein polymer particles of said polymer powder(a) have a particle size ≦500 nm.
 3. The stabilizer mixture as claimedin claim 1, wherein said polymer powder (a) comprises from 0.5 to 50% byweight of the at least one UV absorber, based on the weight of thepolymer matrix.
 4. A process for stabilizing polymer with respect toexposure to UV radiation, oxygen and heat, which comprises adding, tothe polymers, an effective amount of stabilizer mixture as claimed inclaim 1.